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Garnet
Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different species are pyrope, almandine, spessartine, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series: pyrope-almandine-spessartine (pyralspite), with the composition range ; and uvarovite-grossular-andradite (ugrandite), with the composition range . Etymology The word ''garnet'' comes from the 14th-century Middle English word ''gernet'', meaning 'dark red'. It is borrowed from Old French ''grenate'' from Latin ''granatus,'' from ''granum'' ('grain, seed'). This is possibly a reference to ''mela granatum'' or even ''pomum granatum'' (' pomegranate', ''Punica granatum''), a plant whose fruits contain abundant and vivid red seed covers ( arils) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garnet
Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different species are pyrope, almandine, spessartine, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series: pyrope-almandine-spessartine (pyralspite), with the composition range ; and uvarovite-grossular-andradite (ugrandite), with the composition range . Etymology The word ''garnet'' comes from the 14th-century Middle English word ''gernet'', meaning 'dark red'. It is borrowed from Old French ''grenate'' from Latin ''granatus,'' from ''granum'' ('grain, seed'). This is possibly a reference to ''mela granatum'' or even ''pomum granatum'' (' pomegranate', ''Punica granatum''), a plant whose fruits contain abundant and vivid red seed covers ( arils) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garnet S
Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different species are pyrope, almandine, spessartine, grossular (varieties of which are hessonite or cinnamon-stone and tsavorite), uvarovite and andradite. The garnets make up two solid solution series: pyrope-almandine-spessartine (pyralspite), with the composition range ; and uvarovite-grossular-andradite (ugrandite), with the composition range . Etymology The word ''garnet'' comes from the 14th-century Middle English word ''gernet'', meaning 'dark red'. It is borrowed from Old French ''grenate'' from Latin ''granatus,'' from ''granum'' ('grain, seed'). This is possibly a reference to ''mela granatum'' or even ''pomum granatum'' ('pomegranate', ''Punica granatum''), a plant whose fruits contain abundant and vivid red seed covers (arils), which are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrope
The mineral pyrope is a member of the garnet group. Pyrope is the only member of the garnet family to always display red colouration in natural samples, and it is from this characteristic that it gets its name: from the Greek for ''fire'' and ''eye''. Despite being less common than most garnets, it is a widely used gemstone with numerous alternative names, some of which are misnomers. ''Chrome pyrope'', and ''Bohemian garnet'' are two alternative names, the usage of the latter being discouraged by the Gemological Institute of America.(Gia), Gemological. Gem Reference Guide. City: Gemological Institute of America (GIA), 1988. Misnomers include ''Colorado ruby'', ''Arizona ruby'', ''California ruby'', ''Rocky Mountain ruby'', ''Elie Ruby'', ''Bohemian carbuncle'', and ''Cape ruby''. The composition of pure pyrope is Mg3Al2(SiO4)3, although typically other elements are present in at least minor proportions—these other elements include Ca, Cr, Fe and Mn. Pyrope forms a solid so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hessonite
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, ''grossularia'', in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone. In geological literature, grossular has often been called ''grossularite''. Since 1971, however, use of the term grossularite for the mineral has been discouraged by the International Mineralogical Association. Hessonite Hessonite or "cinnamon stone" is a common variety of grossular with the general formula: Ca3Al2Si3O12. The name comes from the grc, ἣσσων (hēssōn), meaning ''inferior''; an allusion to its lower hardness and lower density than most other garnet species varieties. It has a chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grossular
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al2(SiO4)3 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron. The name grossular is derived from the botanical name for the gooseberry, ''grossularia'', in reference to the green garnet of this composition that is found in Siberia. Other shades include cinnamon brown (cinnamon stone variety), red, and yellow. Grossular is a gemstone. In geological literature, grossular has often been called ''grossularite''. Since 1971, however, use of the term grossularite for the mineral has been discouraged by the International Mineralogical Association. Hessonite Hessonite or "cinnamon stone" is a common variety of grossular with the general formula: Ca3Al2Si3O12. The name comes from the grc, ἣσσων (hēssōn), meaning ''inferior''; an allusion to its lower hardness and lower density than most other garnet species varieties. It has a chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uvarovite
Uvarovite is a chromium-bearing garnet group species with the formula: Ca3 Cr2( Si O4)3. It was discovered in 1832 by Germain Henri Hess who named it after Count Sergei Semenovitch Uvarov (1765–1855), a Russian statesman and amateur mineral collector. It is classified in the ugrandite group alongside the other calcium-bearing garnets andradite and grossular. Uvarovite is the rarest of the common members of the garnet group, and is the only consistently green garnet species, with an emerald-green color. It occurs as well-formed fine-sized crystals. Occurrence Uvarovite most commonly occurs in solid solution with grossular or andradite, and is generally found associated with serpentinite, chromite, metamorphic limestones, and skarn ore-bodies. The most significant source of uvarovite historically has been a now-closed copper mine at Outokumpu, Finland, from where most museum specimens have been collected. The uvarovite crystals found in the Outokumpu district are among a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Almandine
Almandine (), also known as almandite, is a species of mineral belonging to the garnet group. The name is a corruption of alabandicus, which is the name applied by Pliny the Elder to a stone found or worked at Alabanda, a town in Caria in Asia Minor. Almandine is an iron alumina garnet, of deep red color, inclining to purple. It is frequently cut with a convex face, or en cabochon, and is then known as carbuncle. Viewed through the spectroscope in a strong light, it generally shows three characteristic absorption bands. Almandine is one end-member of a mineral solid solution series, with the other end member being the garnet pyrope. The almandine crystal formula is: Fe3Al2(SiO4)3. Magnesium substitutes for the iron with increasingly pyrope-rich composition. Almandine, Fe2+3Al2Si3O12, is the ferrous iron end member of the class of garnet minerals representing an important group of rock-forming silicates, which are the main constituents of the Earth's crust, upper mantle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spessartine
Spessartine is a nesosilicate, manganese aluminium garnet species, Mn2+3Al2(SiO4)3.Gemological Institute of America, ''GIA Gem Reference Guide'' 1995, This mineral is sometimes mistakenly referred to as ''spessartite''. Spessartine's name is a derivative of Spessart in Bavaria, Germany, the type locality of the mineral. It occurs most often in granite pegmatite and allied rock types and in certain low-grade metamorphic phyllites. Sources include Australia, Myanmar, India, Afghanistan, Israel, Madagascar, Namibia, Nigeria, Mozambique, Tanzania and the United States. Spessartine of an orange-yellow has been called ''Mandarin garnet'' and is found in Madagascar. Violet-red spessartines are found in rhyolites in Colorado and Maine. In Madagascar, spessartines are exploited either in their bedrock or in alluvium. The orange garnets result from sodium-rich pegmatites. Spessartines are found in bedrock in the highlands in the Sahatany valley. Those in alluvium are generally found in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsavorite
Tsavorite or tsavolite is a variety of the garnet group species grossular, a calcium-aluminium garnet with the formula Ca3 Al2 Si3 O12.Gemological Institute of America, ''GIA Gem Reference Guide'' 1995, Trace amounts of vanadium or chromium provide the green color. In 1967, British gem prospector and geologist Campbell R. Bridges discovered a deposit of green grossular in the mountains of Simanjiro District of Manyara Region of north-east TanzaniaIdar-ObersteinTsavorite International Colored Gemstone Association, accessed online January 24, 2007 in a place called Lemshuko, away from Komolo, the first village. The specimens he found were of very intense color and of high transparency. The find interested the gem trade, and attempts were made to export the stones, but the Tanzanian government did not provide permits. Believing that the deposit was a part of a larger geological structure extending possibly into Kenya, Bridges began prospecting in that nation. He was successful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andradite
Andradite is a mineral species of the garnet group. It is a nesosilicate, with formula Ca3Fe2Si3O12. Andradite includes three varieties: * ''Melanite'': Black in color, referred to as "titanian andradite". Mindat.org * : Vivid green in color, one of the most valuable and rare stones in the world. * ''Topazolite'': Yellow-green in color and sometimes of high enough quality to be cut into a faceted , it is rarer than demantoid. It was first describe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitreous Lustre
Lustre (British 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 exhibit unu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lustre (mineralogy)
Lustre (British 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 exhibit unu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
