SILVER
silver - mineral 1.1.1.2
| Chemical Formula | Ag | |||||||||
| Composition | Silver, sometimes mixed with gold, mercury, arsenic, and antimony | |||||||||
| Variable Formula | (Ag,Au) ; (Ag,Au,Hg,As,Sb) |
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| Color | Silver-white on untarnished surfaces. Tarnishes dark yellow to black. | |||||||||
| Streak | Silver-white to light gray. Streak shiny. | |||||||||
| Hardness | 2½ - 3 | |||||||||
| Crystal Forms and Aggregates |
(Isometric) Cubic, octahedral, and dodecahedral crystals occur, but are very rare. Usually occurs dendritic, wiry, massive, as grains and scales, and as groups of tiny crystals. | |||||||||
| Transparency | Opaque | |||||||||
| Specific Gravity | 9.6 - 12.0 (Pure = 10.5) | |||||||||
| Luster | Metallic | |||||||||
| Cleavage | None | |||||||||
| Fracture | Hackly | |||||||||
| Tenacity | Ductile and Malleable | |||||||||
| Other ID Marks | 1) Tarnish. On a freshly broken surface, the color is
bright metallic-white. Upon oxidation, it tarnishes black, brown to gray, and
dark yellow. 2) Silver is the best conductor of electricity. |
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| Other Names | ||||||||||
| In Group | Native elements ; Metallic elements | |||||||||
| All About | Silver is one of the most famous precious metals, and has been used for ornamental purposes since the earliest of times.
Most silver is extracted from silver ores,
but considerable amounts are mined from Native Silver. Silver can be found pure,
but is usually mixed with small amounts of gold, arsenic,
and antimony. A natural alloy
of gold and silver is known as Electrum, and is
usually classified as a variety of Gold. Silver is a very resistant mineral. It does not dissolve in most solutions, and won't react to oxygen or water. However, it has a detrimental reaction to sulfur and sulfides, which cause it to tarnish on exposed surfaces. Hydrogen sulfide (H2S) is found in the atmosphere in small quantities, and when silver is exposed to normal air it reacts to the hydrogen sulfide, causing the tarnish. Egg yolks, which contain sulfur compounds, should be kept away from silver. Several chemical coats are available to protect it from tarnish, and certain polishes remove tarnish. |
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| Uses | Silver has many unique physical properties that give it very special status. Silver is the best conductor of electricity, is
the second most malleable and ductile metal, and is in
greater abundance than all other precious metals with similar
properties. Due to its unique properties and intrinsic
beauty, it is extensively used industrially
and as ornaments. Silver is largely used as jewelry, ornaments, and coins. It is very easy to work with, and beautiful objects are created from it, such as goblets, candelabras, trays, and cutlery. In the industrial sector, silver is widely used for electrical apparatuses and circuits. It is also used for medicinal purposes, particularly in dentistry, for bactericides, and for antiseptics. Also see the gemstone section on Silver. |
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| Striking Features | Interesting crystal habit, tarnish, ductility, and conductivity | |||||||||
| Complex Tests | Dissolves in nitric and sulfuric acids. | |||||||||
| Popularity (1-4) | 1 | |||||||||
| Prevalence (1-3) | 2 | |||||||||
| Demand (1-3) | 1 | |||||||||
| Distinguishing Similar Minerals |
Platinum - harder (4 - 4½), does not tarnish, heavier (14 - 19), and usually in different
form Galena, Argentite, and Skutterudite - darker color, darker colored streak, usually in different form Molybdenite and Stibnite - softer (2), different crystal form Lead - softer (1.5), oxidizes to a slight bluish-gray color |
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| Commonly Occurs With |
Acanthite, Quartz, Calcite, Copper | |||||||||
| Noteworthy Localities |
Kongsberg, Norway; and Freiberg, Saxony, Germany (especially the Himmelsfürt mine), are perhaps two most classic localities, where beautiful crystals and wiry
masses were once found in abundance, and are greatly cherished by collectors. The finest New World occurrence is Batopilas, Chihuahua, Mexico, where large masses and skeletal agglomerates occur in beautiful form. |
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| Picture Icon Links |
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| Picture Links | 1. Silver dendrite 2. Silver nugget 3. Silver in rock, with vein |
Additional references
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