Search results
Results from the WOW.Com Content Network
Marie Byrd Land. Range coordinates. 85°56′S 132°50′W. / 85.933°S 132.833°W / -85.933; -132.833. The Quartz Hills ( 85°56′S 132°50′W) is an arcuate cluster of largely ice-free hills and peaks found immediately south of Colorado Glacier along the west side of Reedy Glacier. They are part of the Transantarctic Mountains of ...
Chalcedony. Chalcedony (/ kælˈsɛdəni / kal-SED-ə-nee, or / ˈkælsəˌdoʊni / KAL-sə-doh-nee) [2] is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. [3] These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic.
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 a framework silicate mineral ...
Rose quartz (1966) Fairburn agate (1966) and State Jewelry: Black Hills Gold: Tennessee [66] Agate (2009) Limestone (from 1979 to present) and formerly.
Selenite, satin spar, desert rose, and gypsum flower are crystal habit varieties of the mineral gypsum.. All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning that it has two molecules of water), with the chemical formula CaSO 4 ·2H 2 O. Selenite contains no significant selenium – The similar names both derive from Greek selḗnē ...
Rhodonite is a manganese inosilicate, with the formula (Mn, Fe, Mg, Ca)SiO 3, and member of the pyroxenoid group of minerals, crystallizing in the triclinic system. It commonly occurs as cleavable to compact masses with a rose-red color (its name comes from Ancient Greek ῥόδον (rhódon) 'rose'), often tending to brown due to surface oxidation.
Herkimer diamonds are double-terminated quartz crystals discovered within exposed outcrops of dolomite in and around Herkimer County, New York, and the Mohawk River Valley in the US. [1][2] They are not diamonds; the "diamond" in their name is due to both their clarity and well formed faces. Because the first discovery sites were in the village ...
Pegmatite. A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes greater than 1 meter (3 ft). Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic composition to granite.