adulariaagatean impure microcrystalline form of quartz consisting of a variegated, usually banded chalcedony, used as a gemstone and in making pestles and mortars, burnishers, and polishers. Formula: SiO2 alexandritea green variety of chrysoberyl used as a gemstone almandinea deep violet-red garnet that consists of iron aluminium silicate and is used as a gemstone. Formula: Fe3Al2(SiO4)3 amazoniteamethysta purple or violet transparent variety of quartz used as a gemstone. Formula: SiO2 andalusiteandraditea yellow, green, or brownish-black garnet that consists of calcium iron silicate and is used as a gemstone. Formula: Ca3Fe2(SiO4)3 aquamarinea pale greenish-blue transparent variety of beryl used as a gemstone aventurine, aventurin, or avanturinea variety of quartz containing red or greenish particles of iron oxide or mica: a gemstone balasa red variety of spinel, used as a gemstone beryla white, blue, yellow, green, or pink mineral, found in coarse granites and igneous rocks. It is a source of beryllium and is sometimes used as a gemstone; the green variety is emerald, the blue is aquamarine. Composition: beryllium aluminium silicate. Formula: Be3Al2Si6O18. Crystal structure: hexagonal black opalany opal of a dark coloration, not necessarily black bloodstonea dark-green variety of chalcedony with red spots: used as a gemstone bone turquoisecairngorma smoky yellow, grey, or brown variety of quartz, used as a gemstone carneliana red or reddish-yellow translucent variety of chalcedony, used as a gemstone cat's-eyeany of a group of gemstones, esp a greenish-yellow variety of chrysoberyl, that reflect a streak of light when cut in a rounded unfaceted shape chalcedonya microcrystalline often greyish form of quartz with crystals arranged in parallel fibres: a gemstone. Formula: SiO2 chrysoberyla rare very hard greenish-yellow mineral consisting of beryllium aluminate in orthorhombic crystalline form and occurring in coarse granite: used as a gemstone in the form of cat's eye and alexandrite. Formula: BeAl2O4 chrysolitea yellowish-green gem derived chiefly from varieties of olivine chrysoprasean apple-green variety of chalcedony: a gemstone citrinea brownish-yellow variety of quartz: a gemstone; false topaz Colorado rubya fire-red form of garnet found in Colorado and other parts of North America Colorado topaza tawny-coloured form of topaz found in Colorado corunduma white, grey, blue, green, red, yellow, or brown mineral, found in metamorphosed shales and limestones, in veins, and in some igneous rocks. It is used as an abrasive and as gemstone; the red variety is ruby, the blue is sapphire. Composition: aluminium oxide. Formula: Al2O3. Crystal structure: hexagonal (rhombohedral) cymophanea yellow or green opalescent variety of chrysoberyl demantoida bright green variety of andradite garnet diamonddiopsideemeralda green transparent variety of beryl: highly valued as a gem fire opalan orange-red translucent variety of opal, valued as a gemstone garnetgirasol, girosol, or girasolea type of opal that has a red or pink glow in bright light; fire opal grossularitea green or greenish-grey garnet, used as a gemstone. Formula: Ca3Al2(SiO4)3 hawk's-eyehelidorheliotropehessonitean orange-brown variety of grossularite garnet hiddenitea green transparent variety of the mineral spodumene, used as a gemstone hyacintha red or reddish-brown transparent variety of the mineral zircon, used as a gemstone indicolite or indigolitea form of tourmaline ranging in colour from pale blue to blue-black jacinthjadeite or jadea usually green or white mineral of the clinopyroxene group, found in igneous and metamorphic rocks. It is used as a gemstone (jade). Composition: sodium aluminium silicate. Formula: NaAlSi2O6. Crystal structure: monoclinic jasperan opaque impure microcrystalline form of quartz, red, yellow, brown, or dark green in colour, used as a gemstone and for ornamental decoration jetkunzitea pink-coloured transparent variety of the mineral spodumene: a gemstone lapis lazuliliver opala form of opal having a reddish-brown coloration Madagascar aquamarinea form of blue beryl from Madagascar, used as a gemstone melanitea black variety of andradite garnet moonstonea gem variety of orthoclase or albite that is white and translucent with bluish reflections morganitea pink variety of beryl, used as a gemstone moriona smoky brown, grey, or blackish variety of quartz, used as a gemstone moss agatea variety of chalcedony with dark greenish mossy markings, used as a gemstone New Zealand greenstoneodontoliteonyxa variety of chalcedony with alternating black and white parallel bands, used as a gemstone. Formula: SiO2 opalOriental almandinea variety of corundum resembling almandine in colour and used as a gemstone Oriental emeralda green variety of corundum used as a gemstone peridota pale green transparent variety of the olivine chrysolite, used as a gemstone plasmaa green slightly translucent variety of chalcedony, used as a gemstone pyropea deep yellowish-red garnet that consists of magnesium aluminium silicate and is used as a gemstone. Formula: Mg3Al2(SiO4)3 quartza colourless mineral often tinted by impurities, found in igneous, sedimentary, and metamorphic rocks. It is used in the manufacture of glass, abrasives, and cement, and also as a gemstone; the violet-purple variety is amethyst, the brown variety is cairngorm, the yellow variety is citrine, and the pink variety is rose quartz. Composition: silicon dioxide. Formula: SiO2. Crystal structure: hexagonal rhodolitea pale violet or red variety of garnet, used as a gemstone rose quartza rose-pink often translucent variety of quartz that is used for ornaments rubellitea red transparent variety of tourmaline, used as a gemstone rubya deep red transparent precious variety of corundum: occurs naturally in Myanmar and Sri Lanka but is also synthesized. It is used as a gemstone, in lasers, and for bearings and rollers in watchmaking. Formula: Al2O3 sapphireany precious corundum gemstone that is not red, esp the highly valued transparent blue variety. A synthetic form is used in electronics and precision apparatus. Formula: Al2O3 sard or sardinean orange, red, or brown variety of chalcedony, used as a gemstone. Formula: SiO2 sardonyxa variety of chalcedony with alternating reddish-brown and white parallel bands, used as a gemstone. Formula: SiO2 smoky quartzSpanish topazan orange-brown form of quartz, used as a gemstone spessartitea brownish-red garnet that consists of manganese aluminium silicate and is used as a gemstone. Formula: Mn3Al2(SiO4)3 sphenespinelspodumenestaurolitesunstonetitanitetopaza white or colourless mineral often tinted by impurities, found in cavities in igneous rocks and in quartz veins. It is used as a gemstone. Composition: hydrated aluminium silicate. Formula: Al2SiO4(F,OH)2. Crystal structure: orthorhombic topazolitea yellowish-green variety of andradite garnet tourmalineturquoise a greenish-blue fine-grained secondary mineral consisting of hydrated copper aluminium phosphate. It occurs in igneous rocks rich in aluminium and is used as a gemstone uvarovitean emerald-green garnet found in chromium deposits: consists of calcium chromium silicate. Formula: Ca3Cr2(SiO4)3 vesuvianitewater sapphirewhite sapphirea white pure variety of corundum, used as a gemstone zircon ▷ See gem
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Gemstones 的词汇表—— 柯林斯 英语词汇表