The Clogau (pronounced "clog-eye") Gold Mine (also known as Clogau St David's ) is a gold mine near Bontddu in North Wales .
110-575: The Clogau mine was opened to exploit the copper and lead veins in the area north of Bontddu. In 1854, gold was discovered at the mine in a vein of quartz . The main gold-bearing vein was named the "St. David's lode", and in 1860 arrangements were made with the Crown Estate to work the gold commercially. Operations started on 28 August 1860. Clogau produced significant amounts of gold in the 1890s. In 1899, it produced £60,000 worth of gold (equivalent to £8,531,168 in 2023). In 1919, exploration of
220-473: A druse (a layer of crystals lining a void), of which quartz geodes are particularly fine examples. The crystals are attached at one end to the enclosing rock, and only one termination pyramid is present. However, doubly terminated crystals do occur where they develop freely without attachment, for instance, within gypsum . α-quartz crystallizes in the trigonal crystal system, space group P 3 1 21 or P 3 2 21 (space group 152 or 154 resp.) depending on
330-452: A framework silicate mineral and compositionally as an oxide mineral . Quartz is the second most abundant mineral in Earth 's continental crust , behind feldspar . Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral . The transformation from α-quartz to β-quartz takes place abruptly at 573 °C (846 K; 1,063 °F). Since
440-425: A linguistic therapy. According to Ludwig Wittgenstein , for instance, philosophy aims at dispelling misunderstandings to which humans are susceptible due to the confusing structure of ordinary language . Phenomenologists , such as Edmund Husserl , characterize philosophy as a "rigorous science" investigating essences . They practice a radical suspension of theoretical assumptions about reality to get back to
550-560: A pressure cooker . However, the quality and size of the crystals that were produced by these early efforts were poor. Elemental impurity incorporation strongly influences the ability to process and utilize quartz. Naturally occurring quartz crystals of extremely high purity, necessary for the crucibles and other equipment used for growing silicon wafers in the semiconductor industry, are expensive and rare. These high-purity quartz are defined as containing less than 50 ppm of impurity elements. A major mining location for high purity quartz
660-610: A 200 metre long area returned gold grades of 30.2 to 263 grams per tonne, suggesting that previously unrealised supplies of gold could potentially exist. 52°45′42″N 3°57′53″W / 52.7618°N 3.9647°W / 52.7618; -3.9647 Quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide ). The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra , with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2 . Quartz is, therefore, classified structurally as
770-663: A burial context, such as Newgrange or Carrowmore in Ireland . Quartz was also used in Prehistoric Ireland , as well as many other countries, for stone tools ; both vein quartz and rock crystal were knapped as part of the lithic technology of the prehistoric peoples. While jade has been since earliest times the most prized semi-precious stone for carving in East Asia and Pre-Columbian America, in Europe and
880-487: A defining constituent of granite and other felsic igneous rocks . It is very common in sedimentary rocks such as sandstone and shale . It is a common constituent of schist , gneiss , quartzite and other metamorphic rocks . Quartz has the lowest potential for weathering in the Goldich dissolution series and consequently it is very common as a residual mineral in stream sediments and residual soils . Generally
990-545: A doctor diagnoses a disease based on the observed symptoms. Logic also investigates incorrect forms of reasoning. They are called fallacies and are divided into formal and informal fallacies based on whether the source of the error lies only in the form of the argument or also in its content and context. Metaphysics is the study of the most general features of reality , such as existence, objects and their properties , wholes and their parts , space and time , events , and causation . There are disagreements about
1100-444: A great variety of methods to arrive at philosophical knowledge. They include conceptual analysis , reliance on common sense and intuitions , use of thought experiments , analysis of ordinary language , description of experience , and critical questioning . Philosophy is related to many other fields, including the sciences, mathematics , business , law , and journalism . It provides an interdisciplinary perspective and studies
1210-584: A high presence of quartz suggests a " mature " rock, since it indicates the rock has been heavily reworked and quartz was the primary mineral that endured heavy weathering. While the majority of quartz crystallizes from molten magma , quartz also chemically precipitates from hot hydrothermal veins as gangue , sometimes with ore minerals like gold, silver and copper. Large crystals of quartz are found in magmatic pegmatites . Well-formed crystals may reach several meters in length and weigh hundreds of kilograms. The largest documented single crystal of quartz
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#17327811859291320-702: A metaphysical foundation of ethics. The modern period in Chinese philosophy began in the early 20th century and was shaped by the influence of and reactions to Western philosophy. The emergence of Chinese Marxism —which focused on class struggle , socialism , and communism —resulted in a significant transformation of the political landscape. Another development was the emergence of New Confucianism , which aims to modernize and rethink Confucian teachings to explore their compatibility with democratic ideals and modern science. Traditional Japanese philosophy assimilated and synthesized ideas from different traditions, including
1430-468: A noticeable growth in the number of female philosophers , but they still remained underrepresented. Arabic–Persian philosophy arose in the early 9th century CE as a response to discussions in the Islamic theological tradition . Its classical period lasted until the 12th century CE and was strongly influenced by ancient Greek philosophers. It employed their ideas to elaborate and interpret the teachings of
1540-460: A part of intellectual history , but it also investigates questions not covered by intellectual history such as whether the theories of past philosophers are true and have remained philosophically relevant. The history of philosophy is primarily concerned with theories based on rational inquiry and argumentation; some historians understand it in a looser sense that includes myths , religious teachings , and proverbial lore. Influential traditions in
1650-574: A small Brazilian mine, but it is also seen in Lower Silesia in Poland . Naturally occurring prasiolite is also found in the Thunder Bay area of Canada . Quartz crystals have piezoelectric properties; they develop an electric potential upon the application of mechanical stress . Quartz's piezoelectric properties were discovered by Jacques and Pierre Curie in 1880. Quartz is
1760-437: A submicroscopic distribution of colloidal ferric hydroxide impurities. Natural citrines are rare; most commercial citrines are heat-treated amethysts or smoky quartzes . However, a heat-treated amethyst will have small lines in the crystal, as opposed to a natural citrine's cloudy or smoky appearance. It is nearly impossible to differentiate between cut citrine and yellow topaz visually, but they differ in hardness . Brazil
1870-680: A superstition that it would bring prosperity. Citrine was first appreciated as a golden-yellow gemstone in Greece between 300 and 150 BC, during the Hellenistic Age . Yellow quartz was used prior to that to decorate jewelry and tools but it was not highly sought after. Milk quartz or milky quartz is the most common variety of crystalline quartz. The white color is caused by minute fluid inclusions of gas, liquid, or both, trapped during crystal formation, making it of little value for optical and quality gemstone applications. Rose quartz
1980-612: A variety of arguments. Deductive arguments are mainly studied by formal logic. An argument is deductively valid if the truth of its premises ensures the truth of its conclusion. Deductively valid arguments follow a rule of inference , like modus ponens , which has the following logical form : " p ; if p then q ; therefore q ". An example is the argument "today is Sunday; if today is Sunday then I don't have to go to work today; therefore I don't have to go to work today". The premises of non-deductive arguments also support their conclusion, although this support does not guarantee that
2090-494: Is a combination of different parts and attempts to identify what those parts are. An influential theory in this area claims that knowledge has three components: it is a belief that is justified and true . This theory is controversial and the difficulties associated with it are known as the Gettier problem . Alternative views state that knowledge requires additional components, like the absence of luck; different components, like
2200-510: Is a common issue in relation to the sources of knowledge and the justification they offer. It is based on the idea that beliefs require some kind of reason or evidence to be justified. The problem is that the source of justification may itself be in need of another source of justification. This leads to an infinite regress or circular reasoning . Foundationalists avoid this conclusion by arguing that some sources can provide justification without requiring justification themselves. Another solution
2310-542: Is a form of quartz that ranges from a bright vivid violet to a dark or dull lavender shade. The world's largest deposits of amethysts can be found in Brazil, Mexico, Uruguay, Russia, France, Namibia, and Morocco. Sometimes amethyst and citrine are found growing in the same crystal. It is then referred to as ametrine . Amethyst derives its color from traces of iron in its structure. Blue quartz contains inclusions of fibrous magnesio-riebeckite or crocidolite . Inclusions of
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#17327811859292420-419: Is a monoclinic polymorph. Lechatelierite is an amorphous silica glass SiO 2 which is formed by lightning strikes in quartz sand . As quartz is a form of silica, it is a possible cause for concern in various workplaces. Cutting, grinding, chipping, sanding, drilling, and polishing natural and manufactured stone products can release hazardous levels of very small, crystalline silica dust particles into
2530-463: Is a primary identifier for the macrocrystalline varieties. Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent and has often been used for hardstone carvings , such as the Lothair Crystal . Common colored varieties include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others. These color differentiations arise from
2640-561: Is a set of essential features shared by all parts of philosophy. Others see only weaker family resemblances or contend that it is merely an empty blanket term. Precise definitions are often only accepted by theorists belonging to a certain philosophical movement and are revisionistic according to Søren Overgaard et al. in that many presumed parts of philosophy would not deserve the title "philosophy" if they were true. Some definitions characterize philosophy in relation to its method, like pure reasoning. Others focus on its topic, for example, as
2750-400: Is a type of quartz that exhibits a pale pink to rose red hue. The color is usually considered as due to trace amounts of titanium , iron , or manganese in the material. Some rose quartz contains microscopic rutile needles that produce asterism in transmitted light. Recent X-ray diffraction studies suggest that the color is due to thin microscopic fibers of possibly dumortierite within
2860-467: Is also concerned with the moral evaluation of character traits and institutions. It explores what the standards of morality are and how to live a good life. Philosophical ethics addresses such basic questions as "Are moral obligations relative?"; "Which has priority: well-being or obligation?"; and "What gives life meaning?" The main branches of ethics are meta-ethics , normative ethics , and applied ethics . Meta-ethics asks abstract questions about
2970-483: Is an expression of the philosopher's love of wisdom and has the aim of improving one's well-being by leading a reflective life. For example, the Stoics saw philosophy as an exercise to train the mind and thereby achieve eudaimonia and flourish in life. As a discipline, the history of philosophy aims to provide a systematic and chronological exposition of philosophical concepts and doctrines. Some theorists see it as
3080-666: Is and how to acquire it. Ethics investigates moral principles and what constitutes right conduct. Logic is the study of correct reasoning and explores how good arguments can be distinguished from bad ones. Metaphysics examines the most general features of reality , existence, objects , and properties . Other subfields are aesthetics , philosophy of language , philosophy of mind , philosophy of religion , philosophy of science , philosophy of mathematics , philosophy of history , and political philosophy . Within each branch, there are competing schools of philosophy that promote different principles, theories, or methods. Philosophers use
3190-451: Is closely related to the disciplines of logic and linguistics. The philosophy of language rose to particular prominence in the early 20th century in analytic philosophy due to the works of Frege and Russell. One of its central topics is to understand how sentences get their meaning. There are two broad theoretical camps: those emphasizing the formal truth conditions of sentences and those investigating circumstances that determine when it
3300-408: Is concerned with meaning , understanding , or the clarification of language. According to one view, philosophy is conceptual analysis , which involves finding the necessary and sufficient conditions for the application of concepts. Another definition characterizes philosophy as thinking about thinking to emphasize its self-critical, reflective nature. A further approach presents philosophy as
3410-460: Is itself a borrowing from the Latin philosophia . The term philosophy acquired the meanings of "advanced study of the speculative subjects ( logic , ethics , physics , and metaphysics )", "deep wisdom consisting of love of truth and virtuous living", "profound learning as transmitted by the ancient writers", and "the study of the fundamental nature of knowledge , reality , and existence , and
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3520-523: Is often twinned , synthetic quartz is produced for use in industry. Large, flawless, single crystals are synthesized in an autoclave via the hydrothermal process . Like other crystals, quartz may be coated with metal vapors to give it an attractive sheen. Quartz is the most common material identified as the mystical substance maban in Australian Aboriginal mythology . It is found regularly in passage tomb cemeteries in Europe in
3630-475: Is presented by coherentists , who state that a belief is justified if it coheres with other beliefs of the person. Many discussions in epistemology touch on the topic of philosophical skepticism , which raises doubts about some or all claims to knowledge. These doubts are often based on the idea that knowledge requires absolute certainty and that humans are unable to acquire it. Ethics, also known as moral philosophy, studies what constitutes right conduct . It
3740-418: Is sometimes understood as a proper science in its own right. According to some naturalistic philosophers , such as W. V. O. Quine , philosophy is an empirical yet abstract science that is concerned with wide-ranging empirical patterns instead of particular observations. Science-based definitions usually face the problem of explaining why philosophy in its long history has not progressed to the same extent or in
3850-439: Is that actions are in tune with those duties and not what consequences they have. Virtue theorists judge actions based on how the moral character of the agent is expressed. According to this view, actions should conform to what an ideally virtuous agent would do by manifesting virtues like generosity and honesty . Logic is the study of correct reasoning . It aims to understand how to distinguish good from bad arguments . It
3960-719: Is the mineral defining the value of 7 on the Mohs scale of hardness , a qualitative scratch method for determining the hardness of a material to abrasion. The word "quartz" is derived from the German word Quarz , which had the same form in the first half of the 14th century in Middle High German and in East Central German and which came from the Polish dialect term twardy , which corresponds to
4070-468: Is the 1687 book Philosophiæ Naturalis Principia Mathematica by Isaac Newton . This book referred to natural philosophy in its title, but it is today considered a book of physics. The meaning of philosophy changed toward the end of the modern period when it acquired the more narrow meaning common today. In this new sense, the term is mainly associated with philosophical disciplines like metaphysics, epistemology, and ethics. Among other topics, it covers
4180-729: Is the Spruce Pine Gem Mine in Spruce Pine, North Carolina , United States. Quartz may also be found in Caldoveiro Peak , in Asturias , Spain. By the 1930s, the electronics industry had become dependent on quartz crystals. The only source of suitable crystals was Brazil; however, World War II disrupted the supplies from Brazil, so nations attempted to synthesize quartz on a commercial scale. German mineralogist Richard Nacken (1884–1971) achieved some success during
4290-423: Is the leading producer of citrine, with much of its production coming from the state of Rio Grande do Sul . The name is derived from the Latin word citrina which means "yellow" and is also the origin of the word " citron ". Sometimes citrine and amethyst can be found together in the same crystal, which is then referred to as ametrine . Citrine has been referred to as the "merchant's stone" or "money stone", due to
4400-473: Is the relation between reason and revelation . Indian philosophy combines the spiritual problem of how to reach enlightenment with the exploration of the nature of reality and the ways of arriving at knowledge. Chinese philosophy focuses principally on practical issues in relation to right social conduct, government, and self-cultivation . Major branches of philosophy are epistemology , ethics , logic , and metaphysics . Epistemology studies what knowledge
4510-462: Is truth established?"; and "Can we prove causal relations?" Epistemology is primarily interested in declarative knowledge or knowledge of facts, like knowing that Princess Diana died in 1997. But it also investigates practical knowledge , such as knowing how to ride a bicycle, and knowledge by acquaintance , for example, knowing a celebrity personally. One area in epistemology is the analysis of knowledge . It assumes that declarative knowledge
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4620-412: Is used for very accurate measurements of very small mass changes in the quartz crystal microbalance and in thin-film thickness monitors . Almost all the industrial demand for quartz crystal (used primarily in electronics) is met with synthetic quartz produced by the hydrothermal process. However, synthetic crystals are less prized for use as gemstones. The popularity of crystal healing has increased
4730-456: Is usually divided into formal and informal logic . Formal logic uses artificial languages with a precise symbolic representation to investigate arguments. In its search for exact criteria, it examines the structure of arguments to determine whether they are correct or incorrect. Informal logic uses non-formal criteria and standards to assess the correctness of arguments. It relies on additional factors such as content and context. Logic examines
4840-556: Is whether beauty is an objective feature of entities or a subjective aspect of experience. Aesthetic philosophers also investigate the nature of aesthetic experiences and judgments . Further topics include the essence of works of art and the processes involved in creating them. The philosophy of language studies the nature and function of language . It examines the concepts of meaning , reference , and truth. It aims to answer questions such as how words are related to things and how language affects human thought and understanding. It
4950-591: The Czech term tvrdý ("hard"). Some sources, however, attribute the word's origin to the Saxon word Querkluftertz , meaning cross-vein ore . The Ancient Greeks referred to quartz as κρύσταλλος ( krustallos ) derived from the Ancient Greek κρύος ( kruos ) meaning "icy cold", because some philosophers (including Theophrastus ) understood the mineral to be a form of supercooled ice. Today,
5060-527: The Quran . Al-Kindi (801–873 CE) is usually regarded as the first philosopher of this tradition. He translated and interpreted many works of Aristotle and Neoplatonists in his attempt to show that there is a harmony between reason and faith . Avicenna (980–1037 CE) also followed this goal and developed a comprehensive philosophical system to provide a rational understanding of reality encompassing science, religion, and mysticism. Al-Ghazali (1058–1111 CE)
5170-524: The hexagonal crystal system above 573 °C (846 K; 1,063 °F). The ideal crystal shape is a six-sided prism terminating with six-sided pyramid-like rhombohedrons at each end. In nature, quartz crystals are often twinned (with twin right-handed and left-handed quartz crystals), distorted, or so intergrown with adjacent crystals of quartz or other minerals as to only show part of this shape, or to lack obvious crystal faces altogether and appear massive . Well-formed crystals typically form as
5280-420: The "things themselves", that is, as originally given in experience. They contend that this base-level of experience provides the foundation for higher-order theoretical knowledge, and that one needs to understand the former to understand the latter. An early approach found in ancient Greek and Roman philosophy is that philosophy is the spiritual practice of developing one's rational capacities. This practice
5390-620: The 1930s and 1940s. After the war, many laboratories attempted to grow large quartz crystals. In the United States, the U.S. Army Signal Corps contracted with Bell Laboratories and with the Brush Development Company of Cleveland, Ohio to synthesize crystals following Nacken's lead. (Prior to World War II, Brush Development produced piezoelectric crystals for record players.) By 1948, Brush Development had grown crystals that were 1.5 inches (3.8 cm) in diameter,
5500-412: The 5th century CE. Its focus was on religious topics and many thinkers used ancient philosophy to explain and further elaborate Christian doctrines . The Renaissance period started in the 14th century and saw a renewed interest in schools of ancient philosophy, in particular Platonism . Humanism also emerged in this period. The modern period started in the 17th century. One of its central concerns
5610-457: The Earth's crust exposed to high temperatures, thereby damaging materials containing quartz and degrading their physical and mechanical properties. Although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is a secondary identifier for the cryptocrystalline minerals, although it
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#17327811859295720-466: The Middle East the different varieties of quartz were the most commonly used for the various types of jewelry and hardstone carving , including engraved gems and cameo gems , rock crystal vases , and extravagant vessels. The tradition continued to produce objects that were very highly valued until the mid-19th century, when it largely fell from fashion except in jewelry. Cameo technique exploits
5830-441: The air that workers breathe. Crystalline silica of respirable size is a recognized human carcinogen and may lead to other diseases of the lungs such as silicosis and pulmonary fibrosis . Not all varieties of quartz are naturally occurring. Some clear quartz crystals can be treated using heat or gamma-irradiation to induce color where it would not otherwise have occurred naturally. Susceptibility to such treatments depends on
5940-407: The bands of color in onyx and other varieties. Efforts to synthesize quartz began in the mid-nineteenth century as scientists attempted to create minerals under laboratory conditions that mimicked the conditions in which the minerals formed in nature: German geologist Karl Emil von Schafhäutl (1803–1890) was the first person to synthesize quartz when in 1845 he created microscopic quartz crystals in
6050-442: The basic limits of human understanding". Before the modern age, the term philosophy was used in a wide sense. It included most forms of rational inquiry, such as the individual sciences , as its subdisciplines. For instance, natural philosophy was a major branch of philosophy. This branch of philosophy encompassed a wide range of fields, including disciplines like physics, chemistry , and biology . An example of this usage
6160-441: The beginning of the 20th century. It discusses topics such as ethnophilosophy , négritude , pan-Africanism , Marxism, postcolonialism , the role of cultural identity, relativism , epistemological dualism , and the critique of Eurocentrism . Philosophical questions can be grouped into several branches. These groupings allow philosophers to focus on a set of similar topics and interact with other thinkers who are interested in
6270-444: The chirality. Above 573 °C (846 K; 1,063 °F), α-quartz in P 3 1 21 becomes the more symmetric hexagonal P 6 4 22 (space group 181), and α-quartz in P 3 2 21 goes to space group P 6 2 22 (no. 180). These space groups are truly chiral (they each belong to the 11 enantiomorphous pairs). Both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks (SiO 4 tetrahedra in
6380-560: The color red, can exist at different locations at the same time. This is not the case for particulars including individual persons or specific objects. Other metaphysical questions are whether the past fully determines the present and what implications this would have for the existence of free will . There are many other subfields of philosophy besides its core branches. Some of the most prominent are aesthetics, philosophy of language, philosophy of mind, philosophy of religion, philosophy of science, and political philosophy. Aesthetics in
6490-461: The conclusion is true. One form is inductive reasoning . It starts from a set of individual cases and uses generalization to arrive at a universal law governing all cases. An example is the inference that "all ravens are black" based on observations of many individual black ravens. Another form is abductive reasoning . It starts from an observation and concludes that the best explanation of this observation must be true. This happens, for example, when
6600-614: The consequences of the general theories developed by normative ethics in specific situations, for example, in the workplace or for medical treatments. Within contemporary normative ethics, consequentialism, deontology , and virtue ethics are influential schools of thought. Consequentialists judge actions based on their consequences. One such view is utilitarianism , which argues that actions should increase overall happiness while minimizing suffering. Deontologists judge actions based on whether they follow moral duties, such as abstaining from lying or killing. According to them, what matters
6710-466: The crystal structure. Prase is a green variety of quartz. The green color is caused by inclusions of amphibole . Prasiolite , also known as vermarine , is a variety of quartz that is green in color. The green is caused by iron ions. It is a rare mineral in nature and is typically found with amethyst; most "prasiolite" is not natural – it has been artificially produced by heating of amethyst. Since 1950 , almost all natural prasiolite has come from
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#17327811859296820-433: The crystals. Tridymite and cristobalite are high-temperature polymorphs of SiO 2 that occur in high-silica volcanic rocks. Coesite is a denser polymorph of SiO 2 found in some meteorite impact sites and in metamorphic rocks formed at pressures greater than those typical of the Earth's crust. Stishovite is a yet denser and higher-pressure polymorph of SiO 2 found in some meteorite impact sites. Moganite
6930-499: The demand for natural quartz crystals, which are now often mined in developing countries using primitive mining methods, sometimes involving child labor . Philosopher Philosophy ('love of wisdom' in Ancient Greek ) is a systematic study of general and fundamental questions concerning topics like existence , reason , knowledge , value , mind , and language . It is a rational and critical inquiry that reflects on its own methods and assumptions. Historically, many of
7040-400: The emergence and application of formal logic , the focus on the role of language as well as pragmatism , and movements in continental philosophy like phenomenology, existentialism , and post-structuralism . The 20th century saw a rapid expansion of academic philosophy in terms of the number of philosophical publications and philosophers working at academic institutions . There was also
7150-482: The emergence of non-Vedic teachings, like Buddhism and Jainism . Buddhism was founded by Gautama Siddhartha (563–483 BCE), who challenged the Vedic idea of a permanent self and proposed a path to liberate oneself from suffering . Jainism was founded by Mahavira (599–527 BCE), who emphasized non-violence as well as respect toward all forms of life. The subsequent classical period started roughly 200 BCE and
7260-407: The features that all entities have in common. Specific metaphysics is interested in different kinds of being, the features they have, and how they differ from one another. An important area in metaphysics is ontology . Some theorists identify it with general metaphysics. Ontology investigates concepts like being , becoming , and reality. It studies the categories of being and asks what exists on
7370-442: The hands. This idea persisted until at least the 17th century. He also knew of the ability of quartz to split light into a spectrum . In the 17th century, Nicolas Steno 's study of quartz paved the way for modern crystallography . He discovered that regardless of a quartz crystal's size or shape, its long prism faces always joined at a perfect 60° angle. Quartz belongs to the trigonal crystal system at room temperature, and to
7480-539: The history of philosophy include Western , Arabic–Persian , Indian , and Chinese philosophy . Other philosophical traditions are Japanese philosophy , Latin American philosophy , and African philosophy . Western philosophy originated in Ancient Greece in the 6th century BCE with the pre-Socratics . They attempted to provide rational explanations of the cosmos as a whole. The philosophy following them
7590-420: The importance of a strong state and strict laws. Buddhism was introduced to China in the 1st century CE and diversified into new forms of Buddhism . Starting in the 3rd century CE, the school of Xuanxue emerged. It interpreted earlier Daoist works with a specific emphasis on metaphysical explanations. Neo-Confucianism developed in the 11th century CE. It systematized previous Confucian teachings and sought
7700-437: The impurities of phosphate and aluminium that formed crystalline rose quartz, unlike the iron and microscopic dumortierite fibers that formed rose quartz. Smoky quartz is a gray, translucent version of quartz. It ranges in clarity from almost complete transparency to a brownish-gray crystal that is almost opaque. Some can also be black. The translucency results from natural irradiation acting on minute traces of aluminum in
7810-419: The indigenous Shinto religion and Chinese and Indian thought in the forms of Confucianism and Buddhism, both of which entered Japan in the 6th and 7th centuries. Its practice is characterized by active interaction with reality rather than disengaged examination. Neo-Confucianism became an influential school of thought in the 16th century and the following Edo period and prompted a greater focus on language and
7920-511: The individual sciences , such as physics and psychology , formed part of philosophy. However, they are considered separate academic disciplines in the modern sense of the term. Influential traditions in the history of philosophy include Western , Arabic–Persian , Indian , and Chinese philosophy . Western philosophy originated in Ancient Greece and covers a wide area of philosophical subfields. A central topic in Arabic–Persian philosophy
8030-483: The interconnectedness of all things. Latin American philosophy during the colonial period , starting around 1550, was dominated by religious philosophy in the form of scholasticism . Influential topics in the post-colonial period were positivism , the philosophy of liberation , and the exploration of identity and culture. Early African philosophy, like Ubuntu philosophy , was focused on community, morality, and ancestral ideas. Systematic African philosophy emerged at
8140-452: The largest at that time. By the 1950s, hydrothermal synthesis techniques were producing synthetic quartz crystals on an industrial scale, and today virtually all the quartz crystal used in the modern electronics industry is synthetic. An early use of the piezoelectricity of quartz crystals was in phonograph pickups. One of the most common piezoelectric uses of quartz today is as a crystal oscillator . The quartz oscillator or resonator
8250-517: The location from which the quartz was mined. Prasiolite, an olive colored material, is produced by heat treatment; natural prasiolite has also been observed in Lower Silesia in Poland. Although citrine occurs naturally, the majority is the result of heat-treating amethyst or smoky quartz. Carnelian has been heat-treated to deepen its color since prehistoric times. Because natural quartz
8360-551: The manifestation of cognitive virtues instead of justification; or they deny that knowledge can be analyzed in terms of other phenomena. Another area in epistemology asks how people acquire knowledge. Often-discussed sources of knowledge are perception , introspection , memory , inference , and testimony . According to empiricists , all knowledge is based on some form of experience. Rationalists reject this view and hold that some forms of knowledge, like innate knowledge , are not acquired through experience. The regress problem
8470-562: The mine found new gold veins. A new crushing plant was installed and the mine was re-opened. In 1989 the Clogau Gold Mine was re-opened by William Roberts, founder of Clogau Gold of Wales Ltd. Gold extraction re-commenced between 1992 and 1998, with small-scale mining providing the gold for Clogau Gold jewellery. Mining eventually ceased in 1998 due to high cost of mining and diminishing quantities of gold being found. A 2012 report conducted by Snowdon Mining Consultants on behalf of
8580-421: The mineral dumortierite within quartz pieces often result in silky-appearing splotches with a blue hue. Shades of purple or gray sometimes also are present. "Dumortierite quartz" (sometimes called "blue quartz") will sometimes feature contrasting light and dark color zones across the material. "Blue quartz" is a minor gemstone. Citrine is a variety of quartz whose color ranges from pale yellow to brown due to
8690-596: The most fundamental level. Another subfield of metaphysics is philosophical cosmology . It is interested in the essence of the world as a whole. It asks questions including whether the universe has a beginning and an end and whether it was created by something else. A key topic in metaphysics concerns the question of whether reality only consists of physical things like matter and energy. Alternative suggestions are that mental entities (such as souls and experiences ) and abstract entities (such as numbers) exist apart from physical things. Another topic in metaphysics concerns
8800-404: The most influential philosophers of the subsequent period. The increasing influence of Western thought and institutions in the 19th and 20th centuries gave rise to the intellectual movement of Islamic modernism , which aims to understand the relation between traditional Islamic beliefs and modernity. One of the distinguishing features of Indian philosophy is that it integrates the exploration of
8910-472: The natural and social sciences, religion, and mathematics. Epistemology is the branch of philosophy that studies knowledge. It is also known as theory of knowledge and aims to understand what knowledge is, how it arises, what its limits are, and what value it has. It further examines the nature of truth , belief , justification , and rationality . Some of the questions addressed by epistemologists include "By what method(s) can one acquire knowledge?"; "How
9020-504: The natural world. The Kyoto School emerged in the 20th century and integrated Eastern spirituality with Western philosophy in its exploration of concepts like absolute nothingness ( zettai-mu ), place ( basho ), and the self . Latin American philosophy in the pre-colonial period was practiced by indigenous civilizations and explored questions concerning the nature of reality and the role of humans. It has similarities to indigenous North American philosophy , which covered themes such as
9130-455: The nature and sources of morality. It analyzes the meaning of ethical concepts, like right action and obligation . It also investigates whether ethical theories can be true in an absolute sense and how to acquire knowledge of them. Normative ethics encompasses general theories of how to distinguish between right and wrong conduct. It helps guide moral decisions by examining what moral obligations and rights people have. Applied ethics studies
9240-471: The nature of reality, the ways of arriving at knowledge, and the spiritual question of how to reach enlightenment . It started around 900 BCE when the Vedas were written. They are the foundational scriptures of Hinduism and contemplate issues concerning the relation between the self and ultimate reality as well as the question of how souls are reborn based on their past actions . This period also saw
9350-436: The philosophical sense is the field that studies the nature and appreciation of beauty and other aesthetic properties, like the sublime . Although it is often treated together with the philosophy of art , aesthetics is a broader category that encompasses other aspects of experience, such as natural beauty. In a more general sense, aesthetics is "critical reflection on art, culture, and nature ". A key question in aesthetics
9460-417: The precise definition of the term and its meaning has changed throughout the ages. Metaphysicians attempt to answer basic questions including " Why is there something rather than nothing? "; "Of what does reality ultimately consist?"; and "Are humans free?" Metaphysics is sometimes divided into general metaphysics and specific or special metaphysics. General metaphysics investigates being as such. It examines
9570-494: The presence of impurities which change the molecular orbitals, causing some electronic transitions to take place in the visible spectrum causing colors. The most important distinction between types of quartz is that of macrocrystalline (individual crystals visible to the unaided eye) and the microcrystalline or cryptocrystalline varieties ( aggregates of crystals visible only under high magnification). The cryptocrystalline varieties are either translucent or mostly opaque, while
9680-403: The present case). The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, without a change in the way they are linked. However, there is a significant change in volume during this transition, and this can result in significant microfracturing in ceramics during firing, in ornamental stone after a fire and in rocks of
9790-434: The previous majority owners of the mine, Gold Mining Wales Ltd (GMW), suggested that as much as 500,000 ounces of gold could be lying untouched in the area surrounding the mine, giving hope that gold may again be extracted from the Clogau Gold Mine. Alba Mineral Resources are now the majority owner of the mine and are currently drilling to assess the commercial viability of reopening parts of the mine. Previous samples taken from
9900-400: The problem of identity . One question is how much an entity can change while still remaining the same entity. According to one view, entities have essential and accidental features . They can change their accidental features but they cease to be the same entity if they lose an essential feature. A central distinction in metaphysics is between particulars and universals . Universals, like
10010-428: The provocative, vexing, and enduring problems central to the human condition. The philosophical pursuit of wisdom involves asking general and fundamental questions. It often does not result in straightforward answers but may help a person to better understand the topic, examine their life, dispel confusion, and overcome prejudices and self-deceptive ideas associated with common sense. For example, Socrates stated that "
10120-510: The quartz. Additionally, there is a rare type of pink quartz (also frequently called crystalline rose quartz) with color that is thought to be caused by trace amounts of phosphate or aluminium . The color in crystals is apparently photosensitive and subject to fading. The first crystals were found in a pegmatite found near Rumford , Maine , US, and in Minas Gerais , Brazil. The crystals found are more transparent and euhedral, due to
10230-436: The rational study of reality, knowledge, and values. It is distinguished from other disciplines of rational inquiry such as the empirical sciences and mathematics . The practice of philosophy is characterized by several general features: it is a form of rational inquiry, it aims to be systematic, and it tends to critically reflect on its own methods and presuppositions. It requires attentively thinking long and carefully about
10340-488: The same questions. Epistemology, ethics, logic, and metaphysics are sometimes listed as the main branches. There are many other subfields besides them and the different divisions are neither exhaustive nor mutually exclusive. For example, political philosophy, ethics, and aesthetics are sometimes linked under the general heading of value theory as they investigate normative or evaluative aspects. Furthermore, philosophical inquiry sometimes overlaps with other disciplines in
10450-410: The same way as the sciences. This problem is avoided by seeing philosophy as an immature or provisional science whose subdisciplines cease to be philosophy once they have fully developed. In this sense, philosophy is sometimes described as "the midwife of the sciences". Other definitions focus on the contrast between science and philosophy. A common theme among many such conceptions is that philosophy
10560-563: The scope and fundamental concepts of these fields. It also investigates their methods and ethical implications. The word philosophy comes from the Ancient Greek words φίλος ( philos ) ' love ' and σοφία ( sophia ) ' wisdom ' . Some sources say that the term was coined by the pre-Socratic philosopher Pythagoras , but this is not certain. The word entered the English language primarily from Old French and Anglo-Norman starting around 1175 CE. The French philosophie
10670-598: The study of the biggest patterns of the world as a whole or as the attempt to answer the big questions. Such an approach is pursued by Immanuel Kant , who holds that the task of philosophy is united by four questions: "What can I know?"; "What should I do?"; "What may I hope?"; and "What is the human being?" Both approaches have the problem that they are usually either too wide, by including non-philosophical disciplines, or too narrow, by excluding some philosophical sub-disciplines. Many definitions of philosophy emphasize its intimate relation to science. In this sense, philosophy
10780-469: The teachings of Advaita Vedanta to argue that all the different religions are valid paths toward the one divine. Chinese philosophy is particularly interested in practical questions associated with right social conduct, government, and self-cultivation . Many schools of thought emerged in the 6th century BCE in competing attempts to resolve the political turbulence of that period. The most prominent among them were Confucianism and Daoism . Confucianism
10890-516: The term rock crystal is sometimes used as an alternative name for transparent coarsely crystalline quartz. Roman naturalist Pliny the Elder believed quartz to be water ice , permanently frozen after great lengths of time. He supported this idea by saying that quartz is found near glaciers in the Alps, but not on volcanic mountains, and that large quartz crystals were fashioned into spheres to cool
11000-438: The transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones . Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings , especially in Europe and Asia. Quartz
11110-414: The transparent varieties tend to be macrocrystalline. Chalcedony is a cryptocrystalline form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite . Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate , carnelian or sard, onyx , heliotrope , and jasper . Amethyst
11220-601: The unexamined life is not worth living " to highlight the role of philosophical inquiry in understanding one's own existence. And according to Bertrand Russell , "the man who has no tincture of philosophy goes through life imprisoned in the prejudices derived from common sense, from the habitual beliefs of his age or his nation, and from convictions which have grown up in his mind without the cooperation or consent of his deliberate reason." Attempts to provide more precise definitions of philosophy are controversial and are studied in metaphilosophy . Some approaches argue that there
11330-472: Was a strong critic of the idea that reason can arrive at a true understanding of reality and God. He formulated a detailed critique of philosophy and tried to assign philosophy a more limited place besides the teachings of the Quran and mystical insight. Following Al-Ghazali and the end of the classical period, the influence of philosophical inquiry waned. Mulla Sadra (1571–1636 CE) is often regarded as one of
11440-437: Was characterized by the emergence of the six orthodox schools of Hinduism : Nyāyá , Vaiśeṣika , Sāṃkhya , Yoga , Mīmāṃsā , and Vedanta . The school of Advaita Vedanta developed later in this period. It was systematized by Adi Shankara ( c. 700 –750 CE), who held that everything is one and that the impression of a universe consisting of many distinct entities is an illusion . A slightly different perspective
11550-660: Was defended by Ramanuja (1017–1137 CE), who founded the school of Vishishtadvaita Vedanta and argued that individual entities are real as aspects or parts of the underlying unity. He also helped to popularize the Bhakti movement , which taught devotion toward the divine as a spiritual path and lasted until the 17th to 18th centuries CE. The modern period began roughly 1800 CE and was shaped by encounters with Western thought. Philosophers tried to formulate comprehensive systems to harmonize diverse philosophical and religious teachings. For example, Swami Vivekananda (1863–1902 CE) used
11660-420: Was first developed by Walter Guyton Cady in 1921. George Washington Pierce designed and patented quartz crystal oscillators in 1923. The quartz clock is a familiar device using the mineral. Warren Marrison created the first quartz oscillator clock based on the work of Cady and Pierce in 1927. The resonant frequency of a quartz crystal oscillator is changed by mechanically loading it, and this principle
11770-541: Was found near Itapore , Goiaz , Brazil; it measured approximately 6.1 m × 1.5 m × 1.5 m (20 ft × 5 ft × 5 ft) and weighed over 39,900 kg (88,000 lb). Quartz is extracted from open pit mines . Miners occasionally use explosives to expose deep pockets of quartz. More frequently, bulldozers and backhoes are used to remove soil and clay and expose quartz veins, which are then worked using hand tools. Care must be taken to avoid sudden temperature changes that may damage
11880-511: Was founded by Confucius (551–479 BCE). It focused on different forms of moral virtues and explored how they lead to harmony in society. Daoism was founded by Laozi (6th century BCE) and examined how humans can live in harmony with nature by following the Dao or the natural order of the universe. Other influential early schools of thought were Mohism , which developed an early form of altruistic consequentialism , and Legalism , which emphasized
11990-512: Was how philosophical and scientific knowledge are created. Specific importance was given to the role of reason and sensory experience . Many of these innovations were used in the Enlightenment movement to challenge traditional authorities. Several attempts to develop comprehensive systems of philosophy were made in the 19th century, for instance, by German idealism and Marxism . Influential developments in 20th-century philosophy were
12100-449: Was shaped by Socrates (469–399 BCE), Plato (427–347 BCE), and Aristotle (384–322 BCE). They expanded the range of topics to questions like how people should act , how to arrive at knowledge , and what the nature of reality and mind is. The later part of the ancient period was marked by the emergence of philosophical movements, for example, Epicureanism , Stoicism , Skepticism , and Neoplatonism . The medieval period started in
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