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129-549: In geology , the term marble refers to metamorphosed limestone , but its use in stonemasonry more broadly encompasses unmetamorphosed limestone. Marble is commonly used for sculpture and as a building material . The word "marble" derives from the Ancient Greek μάρμαρον ( mármaron ), from μάρμαρος ( mármaros ), "crystalline rock, shining stone", perhaps from the verb μαρμαίρω ( marmaírō ), "to flash, sparkle, gleam"; R. S. P. Beekes has suggested that

258-535: A characteristic fabric . All three types may melt again, and when this happens, new magma is formed, from which an igneous rock may once again solidify. Organic matter, such as coal, bitumen, oil, and natural gas, is linked mainly to organic-rich sedimentary rocks. To study all three types of rock, geologists evaluate the minerals of which they are composed and their other physical properties, such as texture and fabric . Geologists also study unlithified materials (referred to as superficial deposits ) that lie above

387-485: A petrographic microscope , where the minerals can be identified through their different properties in plane-polarized and cross-polarized light, including their birefringence , pleochroism , twinning , and interference properties with a conoscopic lens . In the electron microprobe, individual locations are analyzed for their exact chemical compositions and variation in composition within individual crystals. Stable and radioactive isotope studies provide insight into

516-412: A platinum plate which was used as the anode, the cathode being a platinum wire partially submerged into mercury. Electrolysis then gave calcium–mercury and magnesium–mercury amalgams, and distilling off the mercury gave the metal. However, pure calcium cannot be prepared in bulk by this method and a workable commercial process for its production was not found until over a century later. At 3%, calcium

645-470: A recommended exposure limit (REL) of 10 mg/m total exposure and 5 mg/m respiratory exposure over an 8-hour workday. Dust, debris and temperature fluctuations from working marble can endanger the eye health of employees. For the staff involved in marble processing, it is necessary to provide eye protection equipment, and it is recommended to improve the education of all workers on occupational health risks and strengthen preventive measures. As

774-646: A " Pre-Greek origin is probable". This stem is also the ancestor of the English word "marmoreal", meaning "marble-like." While the English term "marble" resembles the French marbre , most other European languages (with words like "marmoreal") more closely resemble the original Ancient Greek. Marble is a rock resulting from metamorphism of sedimentary carbonate rocks , most commonly limestone or dolomite . Metamorphism causes variable re-crystallization of

903-434: A "steady state" with respect to calcium input and output. This has important climatological implications, as the marine calcium cycle is closely tied to the carbon cycle . Many calcium compounds are used in food, as pharmaceuticals, and in medicine, among others. For example, calcium and phosphorus are supplemented in foods through the addition of calcium lactate , calcium diphosphate , and tricalcium phosphate . The last

1032-434: A definite homogeneous chemical composition and an ordered atomic arrangement. Each mineral has distinct physical properties, and there are many tests to determine each of them. Minerals are often identified through these tests. The specimens can be tested for: A rock is any naturally occurring solid mass or aggregate of minerals or mineraloids . Most research in geology is associated with the study of rocks, as they provide

1161-423: A dipositive ion with the stable electron configuration of a noble gas , in this case argon . Hence, calcium is almost always divalent in its compounds, which are usually ionic . Hypothetical univalent salts of calcium would be stable with respect to their elements, but not to disproportionation to the divalent salts and calcium metal, because the enthalpy of formation of MX 2 is much higher than those of

1290-642: A gas had not been recognised by the ancient Romans. In 1789, Antoine Lavoisier suspected that lime might be an oxide of a fundamental chemical element . In his table of the elements, Lavoisier listed five "salifiable earths" (i.e., ores that could be made to react with acids to produce salts ( salis = salt, in Latin): chaux (calcium oxide), magnésie (magnesia, magnesium oxide), baryte (barium sulfate), alumine (alumina, aluminium oxide), and silice (silica, silicon dioxide)). About these "elements", Lavoisier reasoned: We are probably only acquainted as yet with

1419-570: A growth of 12% annually for the 2000–2006 period, compared to 10.5% annually for the 2000–2005 period. The largest dimension marble application is tile. The stone and marble industry is one of the largest industries in Palestine, contributing 20-25% of its total industrial revenues, generating USD $ 400–$ 450 million in revenue annually. The industry employs 15,000–20,000 workers across the West Bank across 1200–1700 facilities, and amounts to 4.5% of

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1548-412: A high pressure of oxygen, and there is some evidence for a yellow superoxide Ca(O 2 ) 2 . Calcium hydroxide, Ca(OH) 2 , is a strong base, though not as strong as the hydroxides of strontium, barium or the alkali metals. All four dihalides of calcium are known. Calcium carbonate (CaCO 3 ) and calcium sulfate (CaSO 4 ) are particularly abundant minerals. Like strontium and barium, as well as

1677-552: A large amount of waste not being land-filled, reducing environmental pollution, thereby realizing the sustainability of marble. Converting waste to generate economic income and restore degraded soil can improve the environment. The nature of marble is soft and porous, so it is easily stained by colored liquids and scratches easily. Maintenance and cleaning is particularly important. Geology Geology (from Ancient Greek γῆ ( gê )  'earth' and λoγία ( -logía )  'study of, discourse')

1806-627: A length of less than a meter. Rocks at the depth to be ductilely stretched are often also metamorphosed. These stretched rocks can also pinch into lenses, known as boudins , after the French word for "sausage" because of their visual similarity. Where rock units slide past one another, strike-slip faults develop in shallow regions, and become shear zones at deeper depths where the rocks deform ductilely. The addition of new rock units, both depositionally and intrusively, often occurs during deformation. Faulting and other deformational processes result in

1935-452: A means to provide information about geological history and the timing of geological events. The principle of uniformitarianism states that the geological processes observed in operation that modify the Earth's crust at present have worked in much the same way over geological time. A fundamental principle of geology advanced by the 18th-century Scottish physician and geologist James Hutton

2064-608: A number of fields, laboratory, and numerical modeling methods to decipher Earth history and to understand the processes that occur on and inside the Earth. In typical geological investigations, geologists use primary information related to petrology (the study of rocks), stratigraphy (the study of sedimentary layers), and structural geology (the study of positions of rock units and their deformation). In many cases, geologists also study modern soils, rivers , landscapes , and glaciers ; investigate past and current life and biogeochemical pathways, and use geophysical methods to investigate

2193-508: A part of the metallic substances existing in nature, as all those which have a stronger affinity to oxygen than carbon possesses, are incapable, hitherto, of being reduced to a metallic state, and consequently, being only presented to our observation under the form of oxyds, are confounded with earths. It is extremely probable that barytes, which we have just now arranged with earths, is in this situation; for in many experiments it exhibits properties nearly approaching to those of metallic bodies. It

2322-642: A potential hazard. Mitigations such as dust filters, or dust suppression are suggested, but more research needs to be carried out on the efficacy of safety measures. In the United States, the Occupational Safety and Health Administration (OSHA) has set the legal limit ( permissible exposure limit ) for marble exposure in the workplace as 15 mg/m total exposure and 5 mg/m respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set

2451-423: A rather high neutron flux to allow short-lived Ca to capture a neutron. Ca is produced by electron capture in the r-process in type Ia supernovae , where high neutron excess and low enough entropy ensures its survival. Ca and Ca are the first "classically stable" nuclides with a 6-neutron or 8-neutron excess respectively. Although extremely neutron-rich for such a light element, Ca is very stable because it

2580-401: A result, when Ca does decay, it does so by double beta decay to Ti instead, being the lightest nuclide known to undergo double beta decay. Ca can also theoretically undergo double beta decay to Ti, but this has never been observed. The most common isotope Ca is also doubly magic and could undergo double electron capture to Ar , but this has likewise never been observed. Calcium is

2709-451: A sedimentary rock. Sedimentary rocks are mainly divided into four categories: sandstone, shale, carbonate, and evaporite. This group of classifications focuses partly on the size of sedimentary particles (sandstone and shale), and partly on mineralogy and formation processes (carbonation and evaporation). Igneous and sedimentary rocks can then be turned into metamorphic rocks by heat and pressure that change its mineral content, resulting in

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2838-499: A single environment and do not necessarily occur in a single order. The Hawaiian Islands , for example, consist almost entirely of layered basaltic lava flows. The sedimentary sequences of the mid-continental United States and the Grand Canyon in the southwestern United States contain almost-undeformed stacks of sedimentary rocks that have remained in place since Cambrian time. Other areas are much more geologically complex. In

2967-425: A typical process using magnesium fluorosilicate (MgSiF 6 ) and hydrochloric acid (HCl) taking place. The resulting calcium hexafluorosilicate (CaSiF 6 ) is bonded to the surface of the marble. This is harder, more glossy and stain resistant compared to the original surface. The other often used method of finishing marble is to polish with oxalic acid (H 2 C 2 O 4 ), an organic acid. The resulting reaction

3096-400: A variety of applications. Dating of lava and volcanic ash layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units that do not contain radioactive isotopes and calibrate relative dating techniques. These methods can also be used to determine ages of pluton emplacement. Thermochemical techniques can be used to determine temperature profiles within

3225-434: A very popular building material. The following table is a summary of the features of Marble. White marble has been prized for its use in sculptures since classical times . This preference has to do with its softness, which made it easier to carve, relative isotropy and homogeneity, and a relative resistance to shattering. Also, the low index of refraction of calcite allows light to penetrate 12.7 to 38 millimeters into

3354-472: Is a cosmogenic nuclide , continuously produced through neutron activation of natural Ca. Many other calcium radioisotopes are known, ranging from Ca to Ca. They are all much shorter-lived than Ca, the most stable being Ca (half-life 163 days) and Ca (half-life 4.54 days). Isotopes lighter than Ca usually undergo beta plus decay to isotopes of potassium, and those heavier than Ca usually undergo beta minus decay to isotopes of scandium , though near

3483-438: Is a doubly magic nucleus , having 20 protons and 28 neutrons arranged in closed shells. Its beta decay to Sc is very hindered because of the gross mismatch of nuclear spin : Ca has zero nuclear spin, being even–even , while Sc has spin 6+, so the decay is forbidden by the conservation of angular momentum . While two excited states of Sc are available for decay as well, they are also forbidden due to their high spins. As

3612-497: Is a better conductor by mass than both due to its very low density. While calcium is infeasible as a conductor for most terrestrial applications as it reacts quickly with atmospheric oxygen, its use as such in space has been considered. The chemistry of calcium is that of a typical heavy alkaline earth metal. For example, calcium spontaneously reacts with water more quickly than magnesium and less quickly than strontium to produce calcium hydroxide and hydrogen gas. It also reacts with

3741-419: Is a branch of natural science concerned with the Earth and other astronomical objects , the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences , including hydrology . It is integrated with Earth system science and planetary science . Geology describes the structure of the Earth on and beneath its surface and

3870-401: Is a rock composed of calcium and magnesium carbonate , mostly white and pink. Common marble varieties are granular limestone or dolomite . The hardness of marble is very high, because the internal structure of the rock is very uniform after long-term natural aging, and the internal stress disappears, so the marble will not be deformed due to temperature, and has strong wear resistance. It is

3999-439: Is a very ductile silvery metal (sometimes described as pale yellow) whose properties are very similar to the heavier elements in its group, strontium , barium , and radium . A calcium atom has twenty electrons, with electron configuration [Ar]4s . Like the other elements placed in group 2 of the periodic table, calcium has two valence electrons in the outermost s-orbital, which are very easily lost in chemical reactions to form

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4128-422: Is accomplished in two primary ways: through faulting and folding . In the shallow crust, where brittle deformation can occur, thrust faults form, which causes the deeper rock to move on top of the shallower rock. Because deeper rock is often older, as noted by the principle of superposition , this can result in older rocks moving on top of younger ones. Movement along faults can result in folding, either because

4257-424: Is also used as a polishing agent in toothpaste and in antacids . Calcium lactobionate is a white powder that is used as a suspending agent for pharmaceuticals. In baking, calcium phosphate is used as a leavening agent . Calcium sulfite is used as a bleach in papermaking and as a disinfectant, calcium silicate is used as a reinforcing agent in rubber, and calcium acetate is a component of liming rosin and

4386-421: Is also used to strengthen aluminium alloys used for bearings, for the control of graphitic carbon in cast iron , and to remove bismuth impurities from lead. Calcium metal is found in some drain cleaners, where it functions to generate heat and calcium hydroxide that saponifies the fats and liquefies the proteins (for example, those in hair) that block drains. Besides metallurgy, the reactivity of calcium

4515-460: Is an intimate coupling between the movement of the plates on the surface and the convection of the mantle (that is, the heat transfer caused by the slow movement of ductile mantle rock). Thus, oceanic parts of plates and the adjoining mantle convection currents always move in the same direction – because the oceanic lithosphere is actually the rigid upper thermal boundary layer of the convecting mantle. This coupling between rigid plates moving on

4644-534: Is as follows: In this case the calcium oxalate (CaC 2 O 4 ) formed in the reaction is washed away with the slurry, leaving a surface that has not been chemically changed. The haloalkaliphilic methylotrophic bacterium Methylophaga murata was isolated from deteriorating marble in the Kremlin . Bacterial and fungal degradation was detected in four samples of marble from Milan Cathedral ; black Cladosporium attacked dried acrylic resin using melanin. Marble

4773-452: Is even possible that all the substances we call earths may be only metallic oxyds, irreducible by any hitherto known process. Calcium, along with its congeners magnesium, strontium, and barium, was first isolated by Humphry Davy in 1808. Following the work of Jöns Jakob Berzelius and Magnus Martin af Pontin on electrolysis , Davy isolated calcium and magnesium by putting a mixture of the respective metal oxides with mercury(II) oxide on

4902-505: Is exploited to remove nitrogen from high-purity argon gas and as a getter for oxygen and nitrogen. It is also used as a reducing agent in the production of chromium , zirconium , thorium , vanadium and uranium . It can also be used to store hydrogen gas, as it reacts with hydrogen to form solid calcium hydride , from which the hydrogen can easily be re-extracted. Calcium isotope fractionation during mineral formation has led to several applications of calcium isotopes. In particular,

5031-433: Is horizontal). The principle of superposition states that a sedimentary rock layer in a tectonically undisturbed sequence is younger than the one beneath it and older than the one above it. Logically a younger layer cannot slip beneath a layer previously deposited. This principle allows sedimentary layers to be viewed as a form of the vertical timeline, a partial or complete record of the time elapsed from deposition of

5160-616: Is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources , understanding natural hazards , remediating environmental problems, and providing insights into past climate change . Geology is a major academic discipline , and it is central to geological engineering and plays an important role in geotechnical engineering . The majority of geological data comes from research on solid Earth materials. Meteorites and other extraterrestrial natural materials are also studied by geological methods. Minerals are naturally occurring elements and compounds with

5289-402: Is less reactive than strontium or barium, the oxide–nitride coating that results in air is stable and lathe machining and other standard metallurgical techniques are suitable for calcium. In the United States and Canada, calcium is instead produced by reducing lime with aluminium at high temperatures. Calcium cycling provides a link between tectonics , climate , and the carbon cycle . In

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5418-453: Is more complicated and involves the bicarbonate ion (HCO 3 ) that forms when CO 2 reacts with water at seawater pH : At seawater pH, most of the dissolved CO 2 is immediately converted back into HCO 3 . The reaction results in a net transport of one molecule of CO 2 from the ocean/atmosphere into the lithosphere . The result is that each Ca ion released by chemical weathering ultimately removes one CO 2 molecule from

5547-484: Is primarily accomplished through normal faulting and through the ductile stretching and thinning. Normal faults drop rock units that are higher below those that are lower. This typically results in younger units ending up below older units. Stretching of units can result in their thinning. In fact, at one location within the Maria Fold and Thrust Belt , the entire sedimentary sequence of the Grand Canyon appears over

5676-568: Is that "the present is the key to the past." In Hutton's words: "the past history of our globe must be explained by what can be seen to be happening now." The principle of intrusive relationships concerns crosscutting intrusions. In geology, when an igneous intrusion cuts across a formation of sedimentary rock , it can be determined that the igneous intrusion is younger than the sedimentary rock. Different types of intrusions include stocks, laccoliths , batholiths , sills and dikes . The principle of cross-cutting relationships pertains to

5805-458: Is the fifth most abundant element in the Earth's crust , and the third most abundant metal behind aluminium and iron . It is also the fourth most abundant element in the lunar highlands . Sedimentary calcium carbonate deposits pervade the Earth's surface as fossilized remains of past marine life; they occur in two forms, the rhombohedral calcite (more common) and the orthorhombic aragonite (forming in more temperate seas). Minerals of

5934-458: Is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium . The most common calcium compound on Earth is calcium carbonate , found in limestone and the fossilised remnants of early sea life; gypsum , anhydrite , fluorite , and apatite are also sources of calcium. The name derives from Latin calx " lime ", which was obtained from heating limestone. Some calcium compounds were known to

6063-425: Is the second-most common isotope. The other four natural isotopes, Ca, Ca, Ca, and Ca, are significantly rarer, each comprising less than 1% of all natural calcium. The four lighter isotopes are mainly products of the oxygen-burning and silicon-burning processes, leaving the two heavier ones to be produced via neutron capture processes. Ca is mostly produced in a "hot" s-process , as its formation requires

6192-523: Is used for geologically young materials containing organic carbon . The geology of an area changes through time as rock units are deposited and inserted, and deformational processes alter their shapes and locations. Rock units are first emplaced either by deposition onto the surface or intrusion into the overlying rock . Deposition can occur when sediments settle onto the surface of the Earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows blanket

6321-503: Is used to make metallic soaps and synthetic resins. Calcium is on the World Health Organization's List of Essential Medicines . Foods rich in calcium include dairy products such as milk and yogurt , cheese , sardines , salmon , soy products, kale , and fortified breakfast cereals . Because of concerns for long-term adverse side effects, including calcification of arteries and kidney stones , both

6450-431: Is very soluble in water, 85% of extracellular calcium is as dicalcium phosphate with a solubility of 2.00  mM , and the hydroxyapatite of bones in an organic matrix is tricalcium phosphate with a solubility of 1000 μM. Calcium is a common constituent of multivitamin dietary supplements , but the composition of calcium complexes in supplements may affect its bioavailability which varies by solubility of

6579-487: The United States (about 2000 to 4000 tonnes per year). Canada and France are also among the minor producers. In 2005, about 24000 tonnes of calcium were produced; about half of the world's extracted calcium is used by the United States, with about 80% of the output used each year. In Russia and China, Davy's method of electrolysis is still used, but is instead applied to molten calcium chloride . Since calcium

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6708-506: The bedrock . This study is often known as Quaternary geology , after the Quaternary period of geologic history, which is the most recent period of geologic time. Magma is the original unlithified source of all igneous rocks . The active flow of molten rock is closely studied in volcanology , and igneous petrology aims to determine the history of igneous rocks from their original molten source to their final crystallization. In

6837-418: The carboxyl groups of glutamic acid or aspartic acid residues; through interacting with phosphorylated serine , tyrosine , or threonine residues; or by being chelated by γ-carboxylated amino acid residues. Trypsin , a digestive enzyme, uses the first method; osteocalcin , a bone matrix protein, uses the third. Some other bone matrix proteins such as osteopontin and bone sialoprotein use both

6966-509: The contraction of muscles , nerve conduction, and the clotting of blood. As a result, intra- and extracellular calcium levels are tightly regulated by the body. Calcium can play this role because the Ca ion forms stable coordination complexes with many organic compounds, especially proteins ; it also forms compounds with a wide range of solubilities, enabling the formation of the skeleton . Calcium ions may be complexed by proteins through binding

7095-493: The dimension stone trade, the term marble is used for any crystalline calcitic rock (and some non-calcitic rocks) useful as building stone. For example, Tennessee marble is really a dense granular fossiliferous gray to pink to maroon Ordovician limestone, that geologists call the Holston Formation . Ashgabat , the capital city of Turkmenistan , was recorded in the 2013 Guinness Book of Records as having

7224-512: The geochemical evolution of rock units. Petrologists can also use fluid inclusion data and perform high temperature and pressure physical experiments to understand the temperatures and pressures at which different mineral phases appear, and how they change through igneous and metamorphic processes. This research can be extrapolated to the field to understand metamorphic processes and the conditions of crystallization of igneous rocks. This work can also help to explain processes that occur within

7353-402: The mantle below (separated within itself by seismic discontinuities at 410 and 660 kilometers), and the outer core and inner core below that. More recently, seismologists have been able to create detailed images of wave speeds inside the earth in the same way a doctor images a body in a CT scan . These images have led to a much more detailed view of the interior of the Earth, and have replaced

7482-496: The nuclear drip lines , proton emission and neutron emission begin to be significant decay modes as well. Like other elements, a variety of processes alter the relative abundance of calcium isotopes. The best studied of these processes is the mass-dependent fractionation of calcium isotopes that accompanies the precipitation of calcium minerals such as calcite , aragonite and apatite from solution. Lighter isotopes are preferentially incorporated into these minerals, leaving

7611-455: The oxygen and nitrogen in air to form a mixture of calcium oxide and calcium nitride . When finely divided, it spontaneously burns in air to produce the nitride. Bulk calcium is less reactive: it quickly forms a hydration coating in moist air, but below 30% relative humidity it may be stored indefinitely at room temperature. Besides the simple oxide CaO, calcium peroxide , CaO 2 , can be made by direct oxidation of calcium metal under

7740-467: The physiological and biochemical processes of organisms and cells : in signal transduction pathways where they act as a second messenger ; in neurotransmitter release from neurons ; in contraction of all muscle cell types; as cofactors in many enzymes ; and in fertilization . Calcium ions outside cells are important for maintaining the potential difference across excitable cell membranes , protein synthesis, and bone formation. Calcium

7869-440: The 1960s, it was discovered that the Earth's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into tectonic plates that move across the plastically deforming, solid, upper mantle, which is called the asthenosphere . This theory is supported by several types of observations, including seafloor spreading and the global distribution of mountain terrain and seismicity. There

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7998-424: The 1997 observation by Skulan and DePaolo that calcium minerals are isotopically lighter than the solutions from which the minerals precipitate is the basis of analogous applications in medicine and in paleoceanography. In animals with skeletons mineralized with calcium, the calcium isotopic composition of soft tissues reflects the relative rate of formation and dissolution of skeletal mineral. In humans, changes in

8127-424: The Earth, such as subduction and magma chamber evolution. Structural geologists use microscopic analysis of oriented thin sections of geological samples to observe the fabric within the rocks, which gives information about strain within the crystalline structure of the rocks. They also plot and combine measurements of geological structures to better understand the orientations of faults and folds to reconstruct

8256-484: The Grand Canyon in the southwestern United States being a very visible example, the lower rock units were metamorphosed and deformed, and then deformation ended and the upper, undeformed units were deposited. Although any amount of rock emplacement and rock deformation can occur, and they can occur any number of times, these concepts provide a guide to understanding the geological history of an area. Geologists use

8385-604: The U.S. Institute of Medicine (IOM) and the European Food Safety Authority (EFSA) set Tolerable Upper Intake Levels (ULs) for combined dietary and supplemental calcium. From the IOM, people of ages 9–18 years are not to exceed 3 g/day combined intake; for ages 19–50, not to exceed 2.5 g/day; for ages 51 and older, not to exceed 2 g/day. EFSA set the UL for all adults at 2.5 g/day, but decided

8514-567: The absence of steric hindrance , smaller group 2 cations tend to form stronger complexes, but when large polydentate macrocycles are involved the trend is reversed. Though calcium is in the same group as magnesium and organomagnesium compounds are very widely used throughout chemistry, organocalcium compounds are not similarly widespread because they are more difficult to make and more reactive, though they have recently been investigated as possible catalysts . Organocalcium compounds tend to be more similar to organoytterbium compounds due to

8643-488: The alkali metals and the divalent lanthanides europium and ytterbium , calcium metal dissolves directly in liquid ammonia to give a dark blue solution. Due to the large size of the calcium ion (Ca ), high coordination numbers are common, up to 24 in some intermetallic compounds such as CaZn 13 . Calcium is readily complexed by oxygen chelates such as EDTA and polyphosphates , which are useful in analytic chemistry and removing calcium ions from hard water . In

8772-423: The ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy , who named the element. Calcium compounds are widely used in many industries: in foods and pharmaceuticals for calcium supplementation , in the paper industry as bleaches, as components in cement and electrical insulators, and in the manufacture of soaps. On

8901-537: The beginning of the 20th century, advancement in geological science was facilitated by the ability to obtain accurate absolute dates to geological events using radioactive isotopes and other methods. This changed the understanding of geological time. Previously, geologists could only use fossils and stratigraphic correlation to date sections of rock relative to one another. With isotopic dates, it became possible to assign absolute ages to rock units, and these absolute dates could be applied to fossil sequences in which there

9030-519: The calcium isotopic composition of urine have been shown to be related to changes in bone mineral balance. When the rate of bone formation exceeds the rate of bone resorption, the Ca/ Ca ratio in soft tissue rises and vice versa. Because of this relationship, calcium isotopic measurements of urine or blood may be useful in the early detection of metabolic bone diseases like osteoporosis . A similar system exists in seawater, where Ca/ Ca tends to rise when

9159-515: The creation of topographic gradients, causing material on the rock unit that is increasing in elevation to be eroded by hillslopes and channels. These sediments are deposited on the rock unit that is going down. Continual motion along the fault maintains the topographic gradient in spite of the movement of sediment and continues to create accommodation space for the material to deposit. Deformational events are often also associated with volcanism and igneous activity. Volcanic ashes and lavas accumulate on

9288-437: The crust, the uplift of mountain ranges, and paleo-topography. Fractionation of the lanthanide series elements is used to compute ages since rocks were removed from the mantle. Other methods are used for more recent events. Optically stimulated luminescence and cosmogenic radionuclide dating are used to date surfaces and/or erosion rates. Dendrochronology can also be used for the dating of landscapes. Radiocarbon dating

9417-483: The excavated material will be waste, this is often then used as chips for flooring or wall finish, and uses for which high-calcium limestone is suitable. Marble sludge waste can be used as a mineral filler in water-based paints. Using ground calcium carbonate as a filler in paint production can improve the brightness, hiding power and application performance of paint, and can also replace expensive pigments such as titanium dioxide . Recycling of marble waste leads to

9546-570: The fault is a normal fault or a thrust fault . The principle of inclusions and components states that, with sedimentary rocks, if inclusions (or clasts ) are found in a formation, then the inclusions must be older than the formation that contains them. For example, in sedimentary rocks, it is common for gravel from an older formation to be ripped up and included in a newer layer. A similar situation with igneous rocks occurs when xenoliths are found. These foreign bodies are picked up as magma or lava flows, and are incorporated, later to cool in

9675-403: The faults are not planar or because rock layers are dragged along, forming drag folds as slip occurs along the fault. Deeper in the Earth, rocks behave plastically and fold instead of faulting. These folds can either be those where the material in the center of the fold buckles upwards, creating " antiforms ", or where it buckles downwards, creating " synforms ". If the tops of the rock units within

9804-453: The favorite medium for Greek and Roman sculptors and architects (see classical sculpture ), marble has become a cultural symbol of tradition and refined taste. Its extremely varied and colorful patterns make it a favorite decorative material. Places named after the stone include Marblehead, Massachusetts ; Marblehead, Ohio ; Marble Arch , London; the Sea of Marmara ; India's Marble Rocks ; and

9933-399: The first and the second. Direct activation of enzymes by binding calcium is common; some other enzymes are activated by noncovalent association with direct calcium-binding enzymes. Calcium also binds to the phospholipid layer of the cell membrane , anchoring proteins associated with the cell surface. As an example of the wide range of solubility of calcium compounds, monocalcium phosphate

10062-747: The first type include limestone , dolomite , marble , chalk , and iceland spar ; aragonite beds make up the Bahamas , the Florida Keys , and the Red Sea basins. Corals , sea shells , and pearls are mostly made up of calcium carbonate. Among the other important minerals of calcium are gypsum (CaSO 4 ·2H 2 O), anhydrite (CaSO 4 ), fluorite (CaF 2 ), and apatite ([Ca 5 (PO 4 ) 3 X], X = OH, Cl, or F).gre The major producers of calcium are China (about 10000 to 12000 tonnes per year), Russia (about 6000 to 8000 tonnes per year), and

10191-483: The folds remain pointing upwards, they are called anticlines and synclines , respectively. If some of the units in the fold are facing downward, the structure is called an overturned anticline or syncline, and if all of the rock units are overturned or the correct up-direction is unknown, they are simply called by the most general terms, antiforms, and synforms. Even higher pressures and temperatures during horizontal shortening can cause both folding and metamorphism of

10320-404: The formation of faults and the age of the sequences through which they cut. Faults are younger than the rocks they cut; accordingly, if a fault is found that penetrates some formations but not those on top of it, then the formations that were cut are older than the fault, and the ones that are not cut must be younger than the fault. Finding the key bed in these situations may help determine whether

10449-436: The formation of "black-crust" (accumulation of calcium sulphate, nitrates and carbon particles). Vinegar and other acidic solutions should be avoided in the cleaning of marble products. Crystallization refers to a method of imparting a glossy, more durable finish on to a marble floor (CaCO 3 ). It involves polishing the surface with an acidic solution and a steel wool pad on a flooring machine. The chemical reaction below shows

10578-415: The formation of bone by allowing and enhancing the deposition of calcium ions there, allowing rapid bone turnover without affecting bone mass or mineral content. When plasma calcium levels fall, cell surface receptors are activated and the secretion of parathyroid hormone occurs; it then proceeds to stimulate the entry of calcium into the plasma pool by taking it from targeted kidney, gut, and bone cells, with

10707-579: The geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth . Geology provides evidence for plate tectonics , the evolutionary history of life , and the Earth's past climates . Geologists broadly study the properties and processes of Earth and other terrestrial planets. Geologists use a wide variety of methods to understand the Earth's structure and evolution, including fieldwork , rock description , geophysical techniques , chemical analysis , physical experiments , and numerical modelling . In practical terms, geology

10836-482: The history of rock deformation in the area. In addition, they perform analog and numerical experiments of rock deformation in large and small settings. Calcium Calcium is a chemical element ; it has symbol Ca and atomic number 20. As an alkaline earth metal , calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium . It

10965-432: The hypothetical MX. This occurs because of the much greater lattice energy afforded by the more highly charged Ca cation compared to the hypothetical Ca cation. Calcium, strontium, barium, and radium are always considered to be alkaline earth metals ; the lighter beryllium and magnesium , also in group 2 of the periodic table, are often included as well. Nevertheless, beryllium and magnesium differ significantly from

11094-417: The information for children and adolescents was not sufficient to determine ULs. Calcium is an essential element needed in large quantities. The Ca ion acts as an electrolyte and is vital to the health of the muscular, circulatory, and digestive systems; is indispensable to the building of bone in the form of hydroxyapatite ; and supports synthesis and function of blood cells. For example, it regulates

11223-423: The internal composition and structure of the Earth. Seismologists can use the arrival times of seismic waves to image the interior of the Earth. Early advances in this field showed the existence of a liquid outer core (where shear waves were not able to propagate) and a dense solid inner core . These advances led to the development of a layered model of the Earth, with a lithosphere (including crust) on top,

11352-464: The later end of the scale, it is marked by the present day (in the Holocene epoch ). The following five timelines show the geologic time scale to scale. The first shows the entire time from the formation of the Earth to the present, but this gives little space for the most recent eon. The second timeline shows an expanded view of the most recent eon. In a similar way, the most recent era is expanded in

11481-564: The limestone. Green coloration is often due to serpentine resulting from originally magnesium-rich limestone or dolomite with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure and heat of the metamorphism. Acids react with the calcium carbonate in marble, producing carbonic acid (which decomposes quickly to CO 2 and H 2 O) and other soluble salts : Outdoor marble statues, gravestones , or other marble structures are damaged by acid rain whether by carbonation , sulfation or

11610-454: The lowest layer to deposition of the highest bed. The principle of faunal succession is based on the appearance of fossils in sedimentary rocks. As organisms exist during the same period throughout the world, their presence or (sometimes) absence provides a relative age of the formations where they appear. Based on principles that William Smith laid out almost a hundred years before the publication of Charles Darwin 's theory of evolution ,

11739-497: The mantle and show the crystallographic structures expected in the inner core of the Earth. The geological time scale encompasses the history of the Earth. It is bracketed at the earliest by the dates of the first Solar System material at 4.567 Ga (or 4.567 billion years ago) and the formation of the Earth at 4.54 Ga (4.54 billion years), which is the beginning of the Hadean eon  – a division of geological time. At

11868-405: The matrix. As a result, xenoliths are older than the rock that contains them. The principle of original horizontality states that the deposition of sediments occurs as essentially horizontal beds. Observation of modern marine and non-marine sediments in a wide variety of environments supports this generalization (although cross-bedding is inclined, the overall orientation of cross-bedded units

11997-501: The most common isotope of calcium in nature is Ca, which makes up 96.941% of all natural calcium. It is produced in the silicon-burning process from fusion of alpha particles and is the heaviest stable nuclide with equal proton and neutron numbers; its occurrence is also supplemented slowly by the decay of primordial K . Adding another alpha particle leads to unstable Ti, which decays via two successive electron captures to stable Ca; this makes up 2.806% of all natural calcium and

12126-544: The nation's GDP. The vast majority of the industry's exports are to Israel. Marble in the geologic sense does not naturally outcrop in Palestine, and that the vast majority of commercially labeled marble produced in Palestine produced would be geologically considered limestone. Particulate air pollution exposure has been found to be elevated in the marble production industry. Exposure to the dust produced by cutting marble could impair lung function or cause lung disease in workers, such as silicosis . Skin and eye problems are also

12255-434: The neighbouring group 2 metals. It crystallises in the face-centered cubic arrangement like strontium and barium; above 443 °C (716 K), it changes to a body-centered cubic . Its density of 1.526 g/cm (at 20 °C) is the lowest in its group. Calcium is harder than lead but can be cut with a knife with effort. While calcium is a poorer conductor of electricity than copper or aluminium by volume, it

12384-525: The only element with two primordial doubly magic isotopes. The experimental lower limits for the half-lives of Ca and Ca are 5.9 × 10 years and 2.8 × 10 years respectively. Apart from the practically stable Ca, the longest lived radioisotope of calcium is Ca. It decays by electron capture to stable K with a half-life of about 10 years. Its existence in the early Solar System as an extinct radionuclide has been inferred from excesses of K: traces of Ca also still exist today, as it

12513-645: The original carbonate mineral grains. The resulting marble rock is typically composed of an interlocking mosaic of carbonate crystals . Primary sedimentary textures and structures of the original carbonate rock ( protolith ) have typically been modified or destroyed. Pure white marble is the result of metamorphism of a very pure ( silicate -poor) limestone or dolomite protolith. The characteristic swirls and veins of many colored marble varieties, sometimes called striations , are usually due to various mineral impurities such as clay , silt , sand , iron oxides , or chert which were originally present as grains or layers in

12642-419: The other hand increases the compound's solubility, volatility, and kinetic stability. Natural calcium is a mixture of five stable isotopes ( Ca, Ca, Ca, Ca, and Ca) and one isotope with a half-life so long that it is for all practical purposes stable ( Ca , with a half-life of about 4.3 × 10  years). Calcium is the first (lightest) element to have six naturally occurring isotopes. By far

12771-400: The other hand, the metal in pure form has few applications due to its high reactivity; still, in small quantities it is often used as an alloying component in steelmaking, and sometimes, as a calcium–lead alloy, in making automotive batteries. Calcium is the most abundant metal and the fifth-most abundant element in the human body . As electrolytes , calcium ions (Ca ) play a vital role in

12900-428: The other members of the group in their physical and chemical behavior: they behave more like aluminium and zinc respectively and have some of the weaker metallic character of the post-transition metals , which is why the traditional definition of the term "alkaline earth metal" excludes them. Calcium metal melts at 842 °C and boils at 1494 °C; these values are higher than those for magnesium and strontium,

13029-477: The plaster in the tomb of Tutankhamun . The ancient Romans instead used lime mortars made by heating limestone (CaCO 3 ). The name "calcium" itself derives from the Latin word calx "lime". Vitruvius noted that the lime that resulted was lighter than the original limestone, attributing this to the boiling of the water. In 1755, Joseph Black proved that this was due to the loss of carbon dioxide , which as

13158-413: The primary record of the majority of the geological history of the Earth. There are three major types of rock: igneous , sedimentary , and metamorphic . The rock cycle illustrates the relationships among them (see diagram). When a rock solidifies or crystallizes from melt ( magma or lava ), it is an igneous rock . This rock can be weathered and eroded , then redeposited and lithified into

13287-569: The principles of succession developed independently of evolutionary thought. The principle becomes quite complex, however, given the uncertainties of fossilization, localization of fossil types due to lateral changes in habitat ( facies change in sedimentary strata), and that not all fossils formed globally at the same time. Geologists also use methods to determine the absolute age of rock samples and geological events. These dates are useful on their own and may also be used in conjunction with relative dating methods or to calibrate relative methods. At

13416-423: The processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages . By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle

13545-408: The rate of removal of Ca by mineral precipitation exceeds the input of new calcium into the ocean. In 1997, Skulan and DePaolo presented the first evidence of change in seawater Ca/ Ca over geologic time, along with a theoretical explanation of these changes. More recent papers have confirmed this observation, demonstrating that seawater Ca concentration is not constant, and that the ocean is never in

13674-428: The rocks. This metamorphism causes changes in the mineral composition of the rocks; creates a foliation , or planar surface, that is related to mineral growth under stress. This can remove signs of the original textures of the rocks, such as bedding in sedimentary rocks, flow features of lavas , and crystal patterns in crystalline rocks . Extension causes the rock units as a whole to become longer and thinner. This

13803-407: The salt involved: calcium citrate , malate , and lactate are highly bioavailable, while the oxalate is less. Other calcium preparations include calcium carbonate , calcium citrate malate , and calcium gluconate . The intestine absorbs about one-third of calcium eaten as the free ion , and plasma calcium level is then regulated by the kidneys . Parathyroid hormone and vitamin D promote

13932-421: The similar ionic radii of Yb (102 pm) and Ca (100 pm). Most of these compounds can only be prepared at low temperatures; bulky ligands tend to favor stability. For example, calcium di cyclopentadienyl , Ca(C 5 H 5 ) 2 , must be made by directly reacting calcium metal with mercurocene or cyclopentadiene itself; replacing the C 5 H 5 ligand with the bulkier C 5 (CH 3 ) 5 ligand on

14061-500: The simplest terms, mountain-building exposes calcium-bearing rocks such as basalt and granodiorite to chemical weathering and releases Ca into surface water. These ions are transported to the ocean where they react with dissolved CO 2 to form limestone ( CaCO 3 ), which in turn settles to the sea floor where it is incorporated into new rocks. Dissolved CO 2 , along with carbonate and bicarbonate ions, are termed " dissolved inorganic carbon " (DIC). The actual reaction

14190-433: The simplified layered model with a much more dynamic model. Mineralogists have been able to use the pressure and temperature data from the seismic and modeling studies alongside knowledge of the elemental composition of the Earth to reproduce these conditions in experimental settings and measure changes within the crystal structure. These studies explain the chemical changes associated with the major seismic discontinuities in

14319-532: The southwestern United States, sedimentary, volcanic, and intrusive rocks have been metamorphosed, faulted, foliated, and folded. Even older rocks, such as the Acasta gneiss of the Slave craton in northwestern Canada , the oldest known rock in the world have been metamorphosed to the point where their origin is indiscernible without laboratory analysis. In addition, these processes can occur in stages. In many places,

14448-522: The steel and become small and spherical, improving castability, cleanliness and general mechanical properties. Calcium is also used in maintenance-free automotive batteries , in which the use of 0.1% calcium– lead alloys instead of the usual antimony –lead alloys leads to lower water loss and lower self-discharging. Due to the risk of expansion and cracking, aluminium is sometimes also incorporated into these alloys. These lead–calcium alloys are also used in casting, replacing lead–antimony alloys. Calcium

14577-407: The stone before being scattered out, resulting in the characteristic waxy look which brings a lifelike luster to marble sculptures of any kind, which is why many sculptors preferred and still prefer marble for sculpting the human form. Construction marble is a stone which is composed of calcite, dolomite or serpentine that is capable of taking a polish. More generally in construction , specifically

14706-550: The subsurface. Sub-specialities of geology may distinguish endogenous and exogenous geology. Geological field work varies depending on the task at hand. Typical fieldwork could consist of: In addition to identifying rocks in the field ( lithology ), petrologists identify rock samples in the laboratory. Two of the primary methods for identifying rocks in the laboratory are through optical microscopy and by using an electron microprobe . In an optical mineralogy analysis, petrologists analyze thin sections of rock samples using

14835-407: The surface of the Earth and the convecting mantle is called plate tectonics . The development of plate tectonics has provided a physical basis for many observations of the solid Earth . Long linear regions of geological features are explained as plate boundaries: Plate tectonics has provided a mechanism for Alfred Wegener 's theory of continental drift , in which the continents move across

14964-488: The surface of the Earth over geological time. They also provided a driving force for crustal deformation, and a new setting for the observations of structural geology. The power of the theory of plate tectonics lies in its ability to combine all of these observations into a single theory of how the lithosphere moves over the convecting mantle. Advances in seismology , computer modeling , and mineralogy and crystallography at high temperatures and pressures give insights into

15093-479: The surface, and igneous intrusions enter from below. Dikes , long, planar igneous intrusions, enter along cracks, and therefore often form in large numbers in areas that are being actively deformed. This can result in the emplacement of dike swarms , such as those that are observable across the Canadian shield, or rings of dikes around the lava tube of a volcano. All of these processes do not necessarily occur in

15222-742: The surface. Igneous intrusions such as batholiths , laccoliths , dikes , and sills , push upwards into the overlying rock, and crystallize as they intrude. After the initial sequence of rocks has been deposited, the rock units can be deformed and/or metamorphosed . Deformation typically occurs as a result of horizontal shortening, horizontal extension , or side-to-side ( strike-slip ) motion. These structural regimes broadly relate to convergent boundaries , divergent boundaries , and transform boundaries, respectively, between tectonic plates. When rock units are placed under horizontal compression , they shorten and become thicker. Because rock units, other than muds, do not significantly change in volume , this

15351-587: The surficial system (atmosphere, ocean, soils and living organisms), storing it in carbonate rocks where it is likely to stay for hundreds of millions of years. The weathering of calcium from rocks thus scrubs CO 2 from the ocean and atmosphere, exerting a strong long-term effect on climate. The largest use of metallic calcium is in steelmaking , due to its strong chemical affinity for oxygen and sulfur . Its oxides and sulfides, once formed, give liquid lime aluminate and sulfide inclusions in steel which float out; on treatment, these inclusions disperse throughout

15480-473: The surrounding solution enriched in heavier isotopes at a magnitude of roughly 0.025% per atomic mass unit (amu) at room temperature. Mass-dependent differences in calcium isotope composition are conventionally expressed by the ratio of two isotopes (usually Ca/ Ca) in a sample compared to the same ratio in a standard reference material. Ca/ Ca varies by about 1- 2‰ among organisms on Earth. Calcium compounds were known for millennia, though their chemical makeup

15609-407: The third timeline, the most recent period is expanded in the fourth timeline, and the most recent epoch is expanded in the fifth timeline. Horizontal scale is Millions of years (above timelines) / Thousands of years (below timeline) Epochs: Methods for relative dating were developed when geology first emerged as a natural science . Geologists still use the following principles today as

15738-677: The towns of Marble, Minnesota ; Marble, Colorado ; Marble Falls, Texas , and Marble Hill, Manhattan, New York . The Elgin Marbles are marble sculptures from the Parthenon in Athens that are on display in the British Museum . Total world quarrying production in 2019 was approximately 316 million tonnes; however, quarrying waste accounted for 53% of this total production. In the process of marble mining and processing, around half or

15867-654: The widespread exchange of marble objects, including building elements, sculptures, and sarcophagi . There was a significant increase in the distribution of white marble from the late 1st century BC to the end of the 2nd century AD. A gradual decline in distribution started in the third century AD. According to the United States Geological Survey , U.S. domestic marble production in 2006 was 46,400 tons valued at about $ 18.1 million, compared to 72,300 tons valued at $ 18.9 million in 2005. Crushed marble production (for aggregate and industrial uses) in 2006

15996-413: The world's highest concentration of white marble buildings. The extraction of marble is performed by quarrying . Blocks are favoured for most purposes, and can be created through various techniques, including drilling and blasting, water jet and wedge methods. Limestones are often commercially and historically referred to as marble, which differs from the geological definition. In 1998, marble production

16125-752: Was China with a 64% market share, followed by India with 11% and Italy with 5%. White marbles throughout the Mediterranean basin were widely utilized during the Roman period. Extraction centers were unevenly distributed across the Italian Peninsula , mainland Greece , the Aegean Islands , Asia Minor , and smaller hubs like those in the Iberian Peninsula . The need for extensive trade arose due to this imbalance, leading to

16254-465: Was 11.8 million tons valued at $ 116 million, of which 6.5 million tons was finely ground calcium carbonate and the rest was construction aggregate . For comparison, 2005 crushed marble production was 7.76 million tons valued at $ 58.7 million, of which 4.8 million tons was finely ground calcium carbonate and the rest was construction aggregate. U.S. dimension marble demand is about 1.3 million tons. The DSAN World Demand for (finished) Marble Index has shown

16383-615: Was datable material, converting the old relative ages into new absolute ages. For many geological applications, isotope ratios of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature , the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice . These are used in geochronologic and thermochronologic studies. Common methods include uranium–lead dating , potassium–argon dating , argon–argon dating and uranium–thorium dating . These methods are used for

16512-446: Was dominated by 4 countries that accounted for almost half of world production of marble and decorative stone. Italy and China were the world leaders, each representing 16% of world production, while Spain and India produced 9% and 8%, respectively. In 2018 Turkey was the world leader in marble export, with 42% share in global marble trade, followed by Italy with 18% and Greece with 10%. The largest importer of marble in 2018

16641-516: Was not understood until the 17th century. Lime as a building material and as plaster for statues was used as far back as around 7000 BC. The first dated lime kiln dates back to 2500 BC and was found in Khafajah , Mesopotamia . About the same time, dehydrated gypsum (CaSO 4 ·2H 2 O) was being used in the Great Pyramid of Giza . This material would later be used for

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