Silver

Silver is one of the few elements that can be found in nature as both a native element, pure or almost pure, (some other native elements are: gold, copper, iron, diamond and sulphur)  and in chemical combinations such as: Argentite Ag2S, Pyrargyrite Ag3SbS3 and Proustite Ag3AsS3.  It can also occur as a constituent in Lead, Copper, Gold and other ores

Native Silver

Native Silver:	Ag
Habit:	Crystals rear; roughly cubic, octahedral or dodecahedral; commonly in arborescent and wiry forms, also massive, as scales, leafy forms or thin plates, filling vein fractures.
Cleavage and fracture:	None, hackly (it looks smooth but has many burs that can be felt with a light touch)
Tenacity:	Very ductile and malleable
Density:	10.1 - 11.1
Color and streak:	Silver-white,often gray to black due to tarnish
Luster:	Metallic

Native silver occurs, often only in small amounts, in the oxidized zone of ore deposits, as deposits from hydrothermal solutions (of primary origin), with sulphides, zeolites, calcite, barite, fluorite, and quarts as well as arsenides, sulphides of nickel and cobalt, other silver minerals and native copper.

Argentite

Argentite:	Ag2S
Crystal System:	Isometric
Habit:	Crystals cubic, octahedral, rarely dodecahedral and in arborescent, filiform, massive and as coatings
Hardness:	2 - 2.5
Density:	7.2 - 7.4
Color:	Black
Streak:	Black and shining
Luster:	Metallic

Argentite is the most common primary silver bearing mineral.  It occurs widely in hydrothermal sulphide deposits of low temperature range together with ruby silvers (pyrargyrite, proustite) and native silver.  It may occur as microscopic inclusions in galena, when that happens this lead mineral is called argentiferous galena.

Proustite

Crystal System:	Trigonal
Crystal Habits:	include prismatic crystals with rhombohedral and scalenohedral faces forming terminations. There is no perpendicular mirror plane and therefore a hemimorphic crystal can be seen, in some rare examples, with differing terminations at the top and bottom of the crystal. Also found massive.

Herdness:	2 - 2.5

Density:	5.75
Color:	Scarlet-vermilion
Streak:	Vermilion
Luster:	Adamantine

Pyrargyrite

Crystal System:	Triogonal
Crystal Habits:	include prismatic crystals with rhombohedral and scalenohedral faces forming terminations. There is no perpendicular mirror plane and therefore a hemimorphic crystal can be seen, in some rare examples, with differing terminations at the top and bottom of the crystal. Also found massive.

Hardness:

2.5

Desnity:	5.85
Color:	Deep Red
Streak:	Red
Luster:	Adamantine

Proustite is one of only an few sulfides that are not metallic or opaque. In fact it is at times cut for gemstones, although it is far too soft to wear in everyday jewelry. Its color is a bright scarlet red to reddish orange and is distinctive. The nickname "Ruby Silver" has been applied to proustite as well as the closely related mineral pyrargyrite. Pyrargyrite is a silver antimony sulfide and is isostructural with proustite. Isostructural means that the two minerals have the same structure but a different chemistry. There is some substitution of the antimony and arsenic. But in both minerals, the substitution is minor and no solid solution is believed to exist between the two minerals. Pyrargyrite is a silver antimony sulfide and is isostructural with proustite. Isostructural means that the two minerals have the same structure but a different chemistry. There is some substitution of the antimony and arsenic. But in both minerals, the substitution is minor and no solid solution is believed to exist between the two minerals.

Additional information:

Associated Minerals include native silver, tetrahedrite, calcite, quartz, galena, sphalerite and other silver vein minerals. Other Characteristics: A white film forms on the surface of crystals upon exposure to light. Notable Occurrences include Atacama, Chile; silver mines in Saxony Germany; Poorman Mine, Idaho and Chihuahua, Mexico.

Silver like gold is both an industrial mineral prised for its superior electrical conductive and a jewelry/currency metal.  Silver is a critical component in photographic materials which accounts for about 28% of all silver's utilization.  The future for silver as a commodity looks promising as many researchers believe silver will become an important component of emerging fuel cell technology.  The advent of digital photography and improvements in xerography were predicted to impact on the demand for silver, however these technologies have not replaced the need for silver but only moderated the increase in world wide consumption.  Mexico, United States, Canada and Australia produce over 50% of the world's silver.  Silver is one of the many minerals that is recycled or reclaimed from industrial processes on a regular basis.  In 1998 Retread did extensive field work on a Silver, lead, zinc poly-metallic sulfide deposit in the Cassiar district of northern British Columbia.

Silver finds a variety of industrial uses due to its unique chemical and physical properties.  Photographic emulsions contain silver bromide, silvers chloride as well as silver iodide.  Silver's high electrical and thermal conductivity and superior oxidation resistance makes it the element of choice with respect to electrical contacts.  Silver batteries include: silver oxide-potassium hydroxide-zinc secondary(rechargable) types and silver oxide-potassium hydroxide-zinc, as well as silver chloride-seawater-magnesium primary batteries (non rechargeable).

In 1998 world production of silver was 16, 200 metric tonnes and sold for about US$ 5.10/ troy ounce.  A troy ounce is about 31.1 grams and a metric tone contains 1 million grams.

For more information about the element silver and its minerals, or other earth science topics go to our links page or try some of these:

United States Geological Survey (USGS): www.usgs.gov
Minerals by Name: mineral.galleries.com
Minerals Yearbook: minerals.er.usgs.gov
London Metals Exchange: www.lme.co.uk