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Chemical Formula | Ag | ||||||||
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Composition | Silver, frequently mixed with gold; sometimes with mercury, arsenic, and antimony | ||||||||
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Variable Formula | (Ag,Au) ; (Ag,Au,Hg,As,Sb) |
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Color | Silver-white on untarnished surfaces. Tarnishes dark yellow to black. | ||||||||
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Streak | Silver-white to light gray. Streak shiny. | ||||||||
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Hardness | 2½ - 3 | ||||||||
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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. | ||||||||
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Transparency | Opaque | ||||||||
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Specific Gravity | 9.6 - 12.0 (Pure = 10.5) | ||||||||
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Luster | Metallic | ||||||||
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Cleavage | None | ||||||||
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Fracture | Hackly | ||||||||
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Tenacity | Ductile and Malleable | ||||||||
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Other ID Marks | 1) Tarnish. On a freshly broken surface, the color is
bright metallic-white. After a short while (depending on
the conditions), it tarnishes black, brown to gray, and
dark yellow. 2) The best conductor of electricity. |
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Other Names |  Native Silver |
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In Group | Native elements ; Metallic elements | ||||||||
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All About | 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. Its weak point is its reaction to sulfur and sulfides, which cause it to tarnish. 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 large quantities of sulfur dioxide (SO2), as well as sulfur ores, 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 | Most silver is extracted from silver ores,
but considerable amounts are mined from Native Silver.
Silver is one of the best known metals, and for good
reason. Silver is the best conductor of electricity, is
the second most malleable and ductile metal, is in
greater abundance than those metals with similar
properties (i.e. gold and platinum), and has intrinsic
beauty, and therefore it is very much used industrially
and for 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 used for circuits and other electrical apparatuses. It is also used for medicinal purposes, particularly in dentistry, for bactericides, and for antiseptics. In the past, it had been used as the reflective surface for mirrors. Also see the gemstone section on Silver |
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Striking Features | Interesting crystal habit, tarnish, ductility, and conductivity | ||||||||
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Complex Tests | Dissolves in nitric and sulfuric acids. | ||||||||
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Popularity (1-4) | 1 | ||||||||
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Prevalence (1-3) | 2 | ||||||||
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Demand (1-3) | 1 | ||||||||
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Distinguishing Similar Minerals |
Platinum - harder (4 - 4½), does not tarnish, heavier (14 - 19), 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 |
Copper, Acanthite, Argentite, Quartz, Calcite | ||||||||
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Noteworthy Localities |
Some of the finest silver has come Kongsberg, Norway, where beautiful crystals and wiry masses occur with Calcite and silver sulfides. Beautiful Silver specimens are also commonly found throughout Mexico; the most renowned locality being Batopilas, in Chihuahua. Quality specimens are also found in the Czech Republic, the U.S., and Canada. The most famous Canadian locality is at Cobalt, Timiskaming District, Ontario. In the U.S., fabulous Silver masses occur with Copper in the Keweenaw Peninsula in Michigan. This mixture is known as a "Halfbreed". Another famous locality is Bisbee, Cochise Co., Arizona. Australia and Peru also produce considerable amounts of Silver. | ||||||||
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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 |
