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Luminous Gemstones
Folktales about luminous gemstones are an almost worldwide motif in mythology and history among Asian, European, African, and American cultures. Some stories about light-emitting gems may have been based on luminescent and phosphorescent minerals such as diamonds. Mineralogical luminosity First, it will be useful to introduce some mineralogical terminology for gemstones that can glow when exposed to light, friction, or heat. Note that the following discussion will omit modern techniques such as X-rays and ultraviolet light that are too recent to have influenced folklore about luminous gems. Luminescence is spontaneous emission of light by a substance not resulting from heat, as distinguished from incandescence, which is light emitted by a substance as a result of heating. Luminescence is caused by the absorption of energy that is released in small amounts. When the energy comes from light or other electromagnetic radiation, it is referred to as photoluminescence; which is di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescence
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colored visible light. The color of the light emitted depends on the chemical composition of the substance. Fluorescent materials generally cease to glow nearly immediately when the radiation source stops. This distinguishes them from the other type of light emission, phosphorescence. Phosphorescent materials continue to emit light for some time after the radiation stops. This difference in duration is a result of quantum spin effects. Fluorescence occurs when a photon from incoming radiation is absorbed by a molecule, exciting it to a higher energy level, followed by the emission of light as the molecule returns to a lower energy state. The emitted light may have a longer wavelength and, therefore, a lower photon energy than the absorbed radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prafulla Chandra Ray
Sir Prafulla Chandra Ray (also spelled Prafulla Chandra Roy; ''Prôphullô Côndrô Rāẏ''; 2 August 1861 – 16 June 1944) was an Indian chemist, educationist, historian, industrialist and philanthropist. He established the first modern Indian research school in chemistry (post classical age) and is regarded as the Father of Indian Chemistry. The Royal Society of Chemistry honoured his life and work with the first ever Chemical Landmark Plaque outside Europe. He was the founder of Bengal Chemicals & Pharmaceuticals, India's first pharmaceutical company. He is the author of '' A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century'' (1902). Biography Family background Prafulla Chandra Ray was born in the village of Raruli-Katipara, then in Jessore District (now Dighalia, Khulna), in the eastern region of the Bengal Presidency of British India (now Bangladesh) to a Bengali Hindu family. He was the third child and son of Harish Chan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Boyle
Robert Boyle (; 25 January 1627 – 31 December 1691) was an Anglo-Irish natural philosopher, chemist, physicist, Alchemy, alchemist and inventor. Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of modern chemistry, and one of the pioneers of modern experimental scientific method. He is best known for Boyle's law, which describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system. Among his works, ''The Sceptical Chymist'' is seen as a cornerstone book in the field of chemistry. He was a devout and pious Anglican and is noted for his works in theology. Biography Early years Boyle was born at Lismore Castle in County Waterford, in the far south of Ireland, the seventh son and fourteenth child of Richard Boyle, 1st Earl of Cork, the 1st Earl of Cork ("the Great Earl of Cork") and Catherine Fenton Boyle, Catherine Fenton. Lord Cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albertus Magnus
Albertus Magnus ( 1200 – 15 November 1280), also known as Saint Albert the Great, Albert of Swabia, Albert von Bollstadt, or Albert of Cologne, was a German Dominican friar, philosopher, scientist, and bishop, considered one of the greatest medieval philosophers and thinkers. Canonized in 1931, he was known during his lifetime as ''Doctor universalis'' and ''Doctor expertus''; late in his life the sobriquet ''Magnus'' was appended to his name. Scholars such as James A. Weisheipl and Joachim R. Söder have referred to him as the greatest German philosopher and theologian of the Middle Ages. The Catholic Church distinguishes him as one of the Doctors of the Church. Biography It seems likely that Albertus Magnus was born sometime before 1200, given well-attested evidence that he was aged over 80 on his death in 1280. Two later sources say that Albert was about 87 on his death, which has led 1193 to be commonly given as the date of Albert's birth, but this information doe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Heat
'' Red heat'' is a practice of using colours to determine the temperature of metal Red Heat may also refer to: * ''Red Heat'' (1985 film), a 1985 film starring Linda Blair * ''Red Heat'' (1988 film), a 1988 film starring Arnold Schwarzenegger and James Belushi ** ''Red Heat'' (video game), a 1989 video game based on the film * '' Red Heat: Conspiracy, Murder, and the Cold War in the Caribbean'', a 2010 history book by Alex von Tunzelmann * ''Red Heat'', a 2000 album by American jazz bassist Jimmy Haslip See also * Red hot (other) {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topaz
Topaz is a silicate mineral made of aluminium, aluminum and fluorine with the chemical formula aluminium, Alsilicon, Sioxygen, O(fluorine, F, hydroxide, OH). It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden-brown to yellow-orange. Topaz is often treated with heat or radiation to make it a deep blue, reddish-orange, pale green, pink, or purple. Topaz is a nesosilicate mineral, and more specifically, an aluminosilicate mineral. It is one of the hardest naturally occurring minerals and has a relatively low index of refraction. It has the orthorhombic crystal system and a dipyramidial crystal class. It occurs in many places in the world. Some of the most popular places where topaz is sourced are Brazil and Russia. Topaz is often mined in open pit or alluvial settings. Etymology The word "topaz" is usually believed to be derived (via Old French: Topace and Latin: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamonds
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of defects or impurities (about one per million of lattice atoms) can color a diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, oran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sydney Hobart Ball
Sydney Hobart Ball (December 11, 1877 – April 3, 1949) was an American geologist and mining engineer. Educated at the University of Wisconsin, Ball spent his early career in public service. In 1907 he left the US to prospect for minerals in the Belgian Congo for the Forminière company. Ball discovered the first part of the Congo-Angola diamond field, which proved a valuable source of revenue. Returning to America, Ball established a private practice and acted as consultant to a number of public bodies. Early life and career Ball was born in Chicago on December 11, 1877, and attended the University of Wisconsin. His later success as a geologist was recognised in a 1909 list of distinguished alumni by William Herbert Hobbs, who taught at the university from 1889 to 1906. Ball worked as a geologist for the Missouri Bureau of Mines and Geology from 1901–2 before returning to the University to lecture in geology from 1902 to 1903. He became an assistant geologist to the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoluminescence Dating
Thermoluminescence dating (TL) is the determination, by means of measuring the accumulated radiation dose, of the time elapsed since material containing crystalline minerals was either heated (lava, ceramics) or exposed to sunlight (sediments). As a crystalline material is heated during measurements, the process of thermoluminescence starts. Thermoluminescence emits a weak light signal that is proportional to the radiation dose absorbed by the material. It is a type of luminescence dating. The technique has wide application, and is relatively cheap at some US$300–700 per object; ideally a number of samples are tested. Sediments are more expensive to date. , University of Wollongong, Australia [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermoluminescence
Thermoluminescence is a form of luminescence that is exhibited by certain crystalline materials, such as some minerals, when previously absorbed energy from electromagnetic radiation or other ionizing radiation is re-emitted as light upon heating of the material. The phenomenon is distinct from that of black-body radiation. Physics High energy radiation creates electronic excited states in crystalline materials. In some materials, these states are ''trapped'', or ''arrested'', for extended periods of time by localized defects, or imperfections, in the lattice interrupting the normal intermolecular or inter-atomic interactions in the crystal lattice. Quantum-mechanically, these states are stationary states which have no formal time dependence; however, they are not stable energetically, as vacuum fluctuations are always "prodding" these states. Heating the material enables the trapped states to interact with phonons, i.e. lattice vibrations, to rapidly decay into lower-energy s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Bond
A chemical bond is the association of atoms or ions to form molecules, crystals, and other structures. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds, or some combination of these effects. Chemical bonds are described as having different strengths: there are "strong bonds" or "primary bonds" such as covalent, ionic and metallic bonds, and "weak bonds" or "secondary bonds" such as dipole–dipole interactions, the London dispersion force, and hydrogen bonding. Since opposite electric charges attract, the negatively charged electrons surrounding the nucleus and the positively charged protons within a nucleus attract each other. Electrons shared between two nuclei will be attracted to both of them. "Constructive quantum mechanical wavefunction interference" stabilizes the paired nuclei (see Theories of chemical bonding). Bonded nuclei maintain an optima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
