Silver

Object/Artifact

-

Crater Rock Museum

Name/Title

Silver

Entry/Object ID

2014.1.121

Description

Assemblage Zone: pegmatite dikes Chemical Composition: Ag, Elemental silver Crystal System: Tetragonal System Description: Common Name: Silver Group Name:Metal Chemistry: Ag, Elemental silver Location: Arizona Description: Dark and gray strand that looks like a dried worm with two heads. Very fragile, so it's displayed in a plastic cube. PHYSICAL CHARACTERISTICS: Color is silver white with exposed specimens tarnishing black. Luster is metallic. Transparency is opaque. Crystal System is isometric; 4/m bar 3 2/m Crystal Habits include massive and disseminated grains, wires and plates as the most common, whole individual crystals are extremely rare but when present are usually cubes, dodecahedrons and octahedrons. "Jack Frost" type crystal growth as shown on some specimens produces beautiful intricate structures. Wires can form coiled clusters that resemble rams horns. Cleavage is absent. Fracture is jagged. Streak is silver white. Hardness is 2.5-3. Specific Gravity is variable according to purity 10-12 (well above average even for metallic minerals) Associated Minerals are silver minerals such as acanthite and prousite, cobaltite, copper, zeolites and quartz. Other Characteristics: ductile, malleable and sectile, meaning it can be pounded into other shapes, stretched into a wire and cut into slices.it. Fracture: jagged Hardness: 2 Gypsum Luster: Metallic Occurrence: Silver is found in native form, alloyed with gold or combined with sulfur, arsenic, antimony or chlorine in ores such as argentite (Ag2S), horn silver (AgCl), and pyrargyrite (Ag3SbS3). The principal sources of silver are the ores of copper, copper-nickel, lead, and lead-zinc obtained from Peru, Mexico, China, Australia, Chile, Poland and Kosovo.[6] Peru and Mexico have been mining silver since 1546 and are still major world producers. Top silver-producing mines are Proaño / Fresnillo (Mexico), Cannington (Queensland, Australia), Dukat (Russia), Uchucchacua (Peru) and Greens Creek mine (Alaska).[32] The metal can also be produced during the electrolytic refining of copper and by the application of the Parkes process on lead metal obtained from lead ores that contain small amounts of silver. Commercial-grade fine silver is at least 99.9% pure silver, and purities greater than 99.999% are available. In 2007, Peru was the world's top producer of silver, closely followed by Mexico, according to the British Geological Survey. Notable Occurrences include Michigan and Arizona, USA; Cobalt, Ontario; Chile; and Germany. Best Field Indicators are color, tarnish, ductility and crystal hab Specific Gravity: 10-12 Streak: silver white Variety: Silver has been mined for eons and has always been popular in jewelry and for coinage. Only in the past hundred years however, has the demand for silver been so great. The reason for this demand is the use of silver in the photography industry, which takes advantage of silver's reactivity to light. Native Silver is rare and much silver is produced from silver-bearing minerals such as prousite, pyrargyrite, galena, etc. Specimens of Native Silver usually consist of wires that are curved and intertwined together, making an inspiring mineralogical curiosity.

Collection

RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Dimensions

Length

1-1/2 in

Dimension Notes

Dimension taken at widest points

Location

Location

Shelf

CS-I-3

Room

Curation Storage

Building

Crater Rock Museum

Category

Storage

Moved By

Jillian Mather Kettley

Date

February 7, 2024