Tellurium (Moctezuma, Mexico) : 無料・フリー素材/写真
Tellurium (Moctezuma, Mexico) / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Tellurium from Mexico. (public display, Montana Bureau of Mines and Geology Mineral Museum, Butte, Montana, USA)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 4900 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.Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals. To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.Tellurium (Te) is a semimetal/metalloid that can occur in its native state as a mineral. It has a metallic luster, a bright silvery color, a grayish streak, is rather soft (H = 2 to 2.5), and is heavy for its size. It is not malleable. Tellurium can break along several cleavage planes. Tellurium is best known from precious metal telluride deposits, such as the Cripple Creek Mining District of Colorado, USA. In such deposits, Te is usually mixed with various metals and semimetals (e.g., Au, Ag, Pb, Ni, Fe, Bi, Sb). |
| 撮影日 | 2011-08-14 12:52:49 |
| 撮影者 | James St. John |
| タグ | |
| 撮影地 |