Kunzite 3 : 無料・フリー素材/写真
Kunzite 3 / James St. John
ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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説明 | (~1.2 centimeter across)--------------------------------------A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 6100 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.The silicates are the most abundant and chemically complex group of minerals. All silicates have silica as the basis for their chemistry. "Silica" refers to SiO2 chemistry. The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4. Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens "belong" to each silicon. The resulting formula for silica is thus SiO2, not SiO4. The simplest and most abundant silicate mineral in the Earth's crust is quartz (SiO2). All other silicates have silica + impurities. Many silicates have a significant percentage of aluminum (the aluminosilicates).Kunzite is a pinkish-purplish, gem-quality variety of spodumene, a lithium aluminosilicate mineral - LiAlSi2O6. Spodumene is usually grouped with the pyroxenes. It has a nonmetallic luster that ranges from glassy on fresh specimens to dull on weathered/altered specimens. It can look like feldspar. Weathered/altered spodumene in mine dumps often has the appearance of wood ("decayed spodumene"). Spodumene is fairly hard (H=6.5 to 7), varies in color, and has two cleavage planes at nearly perfect corners (near 90º). Crystals show striations trending along the long axis.Locality: undisclosed----------------------Photo gallery of kunzite:www.mindat.org/gallery.php?min= 2289----------------------Photo gallery of spodumene:www.mindat.org/gallery.php?min= 3733 |
撮影日 | 2022-12-11 20:10:58 |
撮影者 | James St. John |
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