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Jargoon
Jargoon or jargon (occasionally in old writings jargounce and jacounce) is a name applied by gemologists to zircons that are of sufficient quality to be cut as gemstones, but not the red color that characterizes the ''hyacinth'' or jacinth. The word is related to Persian (zircon; ''zar-gun'', "gold-like" or "as gold"). Some of the finest jargoons are green, others brown and yellow, while some are colorless. The colorless jargoon may be obtained by heating certain colored stones. When zircon is heated it sometimes changes color, or loses it, and at the same time usually increases in density and brilliancy. The so-called ''Matura'' diamonds, formerly sent from Matara (or Matura) in Sri Lanka, were decolorized zircons. The zircon has strong refractive power, and its lustre approaches adamantine, but it lacks the fire of diamond. The specific gravity of zircon is subject to variation in different varieties; thus Sir A. H. Church found the specific gravity of a fine leaf-green j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemology
Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a specific interdisciplinary branch of mineralogy. Some jewellery, jewelers (and many non-jewelers) are academically trained gemologists and are qualified to identify and evaluate gems. History Rudimentary education in gemology for jewellers and gemologists began in the nineteenth century, but the first qualifications were instigated after the National Association of Goldsmiths of Great Britain (NAG) set up as an Education Committee for this purpose in 1908. The committee emerged as a distinct branch of NAG (named the Gemmological Association) in 1931, shortly after the incorporation of the Gemological Institute of America (GIA). In 1938 the branch was renamed as the Gemmological Association of Great Britain, before being incorporated in 1847. The organisation is now an educational charity and accredited awarding body with its courses taught worldwide. The first US graduate of Gem-A' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zircon
Zircon () is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is Zr SiO4. An empirical formula showing some of the range of substitution in zircon is (Zr1–y, REEy)(SiO4)1–x(OH)4x–y. Zircon precipitates from silicate melts and has relatively high concentrations of high field strength incompatible elements. For example, hafnium is almost always present in quantities ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal system. The natural color of zircon varies between colorless, yellow-golden, red, brown, blue, and green. The name derives from the Persian ''zargun'', meaning "gold-hued". This word is changed into " jargoon", a term applied to light-colored zircons. The English word "zircon" is derived from ''Zirkon'', which is the German adaptation of this word. Yellow, orange, and red zircon is also known as " hyacint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemstone
A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewellery, jewelry or other adornments. Certain Rock (geology), rocks (such as lapis lazuli, opal, and obsidian) and occasionally organic chemistry, organic materials that are not minerals (such as amber, Jet (gemstone), jet, and pearl) may also be used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some softer minerals such as brazilianite may be used in jewelry because of their color or Lustre (mineralogy), luster or other physical properties that have aesthetic value. However, generally speaking, soft minerals are not typically used as gemstones by virtue of their brittleness and lack of durability. Found all over the world, the industry of coloured gemstones (i.e. anything other than diamonds) is currently estimated at US$1.55billion and is projected to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacinth
Jacinth (, ) or hyacinth () is a yellow-red to red-brown variety of zircon used as a gemstone. In Exodus 28:19, one of the precious stones set into the ''hoshen'' (the breastplate worn by the High Priest of Israel) is called, in Hebrew, '' leshem'', which is often translated into English as "jacinth". The true identity of this stone has been a source of confusion since at least the first century; the modern identification of ''leshem'' with jacinth seems to have been popularised by Martin Luther, who may in turn have been following a fourth-century tradition. In Revelation 21:20, one of the foundation stones of the New Jerusalem is hyacinth (Greek: ''hyakinthos''). However, ''Strong's Concordance'' and ''Thayer's Greek Lexicon'' describe this as a stone of the colour of the hyacinth plant, i.e. dark blue. The stone intended may be the sapphire Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide () with trace amounts of ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persian Language
Persian ( ), also known by its endonym and exonym, endonym Farsi (, Fārsī ), is a Western Iranian languages, Western Iranian language belonging to the Iranian languages, Iranian branch of the Indo-Iranian languages, Indo-Iranian subdivision of the Indo-European languages. Persian is a pluricentric language predominantly spoken and used officially within Iran, Afghanistan, and Tajikistan in three mutual intelligibility, mutually intelligible standard language, standard varieties, respectively Iranian Persian (officially known as ''Persian''), Dari, Dari Persian (officially known as ''Dari'' since 1964), and Tajik language, Tajiki Persian (officially known as ''Tajik'' since 1999).Siddikzoda, S. "Tajik Language: Farsi or not Farsi?" in ''Media Insight Central Asia #27'', August 2002. It is also spoken natively in the Tajik variety by a significant population within Uzbekistan, as well as within other regions with a Persianate society, Persianate history in the cultural sphere o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matara, Sri Lanka
Matara (; ) is a major city in Sri Lanka, on the southern coast of Southern Province, Sri Lanka, Southern Province. It is the second largest city in Southern Province, Sri Lanka, Southern Province. It is from Colombo. It is a major commercial hub, the administrative capital and largest city of Matara District. Ethnic composition in Matara DS Division according to 2012 census data is Sinhalese 111,039-95.88%, Muslims 4,296-3.71%, Tamils 326-0.28%, Others 144-0.12%. Etymology Consisting of two elements, the term Matara gives its meaning as ''the Great Ferry'', that may be the meaning "great seaport" or "great fortress". It is also thought as being derived from the mispronunciation of the word 'Matora' by the Portuguese who called it 'Mature' or ''Maturai'' in 1672. The native word 'Matora' might also derived from 'Maha Tera' meaning the place where the Great River was crossed. It was also called 'Maha Tota' (Malo Tota) or Maha-Pattana, the great ferry.''Maha Ethara'' meani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, Indian peninsula by the Gulf of Mannar and the Palk Strait. It shares a maritime border with the Maldives in the southwest and India in the northwest. Sri Jayawardenepura Kotte is the legislative capital of Sri Lanka, while the largest city, Colombo, is the administrative and judicial capital which is the nation's political, financial and cultural centre. Kandy is the second-largest urban area and also the capital of the last native kingdom of Sri Lanka. The most spoken language Sinhala language, Sinhala, is spoken by the majority of the population (approximately 17 million). Tamil language, Tamil is also spoken by approximately five million people, making it the second most-spoken language in Sri Lanka. Sri Lanka has a population of appr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lustre (mineralogy)
Lustre (Commonwealth English) or luster (American English; see spelling differences) is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the Latin ''lux'', meaning "light", and generally implies radiance, gloss, or brilliance. A range of terms are used to describe lustre, such as ''earthy'', ''metallic'', ''greasy'', and ''silky''. Similarly, the term ''vitreous'' (derived from the Latin for glass, ''vitrum'') refers to a glassy lustre. A list of these terms is given below. Lustre varies over a wide continuum, and so there are no rigid boundaries between the different types of lustre. (For this reason, different sources can often describe the same mineral differently. This ambiguity is further complicated by lustre's ability to vary widely within a particular mineral species). The terms are frequently combined to describe intermediate types of lustre (for example, a "vitreous greasy" lustre). Some minerals exhib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Gravity
Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nearly always measured with respect to water at its densest (at ); for gases, the reference is air at room temperature (). The term "relative density" (abbreviated r.d. or RD) is preferred in SI, whereas the term "specific gravity" is gradually being abandoned. If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water, then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Herbert Church
Sir Arthur Herbert Church (2 June 1834 – 31 May 1915) was a British chemist, expert on pottery, stones and chemistry of paintings, who discovered turacin in 1869 and several minerals, including the only British cerium mineral. He was also a talented artist and worked as a professor of chemistry at the Agricultural College in Cirencester and then at the Royal Academy of Arts. He wrote extensively on aspects of chemistry in agriculture, art, and daily life. He wrote a widely used book on paints, "The Chemistry of Paints and Painting". Early life Church was born in London, the son of John Thomas Church, a solicitor. His studied at King's College London where he showed an interest in both science and art. He spent four years from 1851 to 1855 at the Royal College of Chemistry where he, under A. W. Hofmann, studied alongside William Henry Perkin with whom he published his first research paper. The next four years were spent at Lincoln College, Oxford, where he received a BA in 1859 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthur Harry Church
Arthur Harry Church Fellow of the Royal Society, FRS (28 March 1865 – 24 April 1937) was a British botanist and botanical illustrator. He was also a pioneer amateur photographer. From 1908 to his retirement in 1930 he was a lecturer in botany at Oxford University and was best known for his inspiring lectures. Biography Church was born in Plymouth, England, the son of a saddler, and went to school locally. He taught briefly at Ashburton Grammar School. In 1887 his mother died and, with his inheritance of £100, he went to University College of Wales, Aberystwyth. With a first (University of London, London external) degree in Botany he won in 1891 a scholarship to Jesus College, Oxford, obtaining a first-class University of Oxford, Oxford degree in botany in 1894. He was a Oxbridge Fellow, research fellow of Jesus College from 1908 to 1912 and University Reader (academic rank), Reader in Botany from 1910 to 1930. He was elected as a Fellow of the Royal Society in 1921. His parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
