Pyrargyrite Value, Price, and Jewelry Information

Rob Lavinsky, iRocks.com – CC-BY-SA-3.0 [CC-BY-SA-3.0], via Wikimedia Commons

Pyrargyrite

Pyrargyrite is found in a number of localities in well-formed crystals, but these are usually small. However, larger, transparent crystals from Bolivia and Chile have provided a limited amount of cuttable rough. Stones approaching 50 carats have been cut, but these tend to be too dark to be really attractive. They are exceedingly rare, however, since pyrargyrite is seldom transparent, usually even less so than the related sulfide, proustite.

Pyrargyrite Information

Data Value
Name Pyrargyrite
Colors Dark red.
Crystallography Hexagonal (R); crystals prismatic, often hemimorphic. Usually massive, compact, disseminated.
Refractive Index 2.88-3.08
Luster Adamantine.
Hardness 2.5
Fracture Conchoidal to uneven
Specific Gravity 5.85.
Birefringence 0.200
Cleavage Distinct 1 direction
Luminescence None reported.
Luminescence Present No
Transparency Translucent to opaque, rarely transparent.
Absorption Spectrum Not diagnostic.
Formula

Ag3SbS3. Related to proustite.

Pleochroism

None observed.

Optics

o = 3.08; e = 2.88. (Note: these reported measurements were made using the Li line at 6710 rather than the customary Na line at 5890). Uniaxial (-).

Optic Sign Uniaxial -

Streak: Purplish red.

Optics: o = 3.08; e=2.88.

(Note: these reported measurements were made using the Li line at 6710 rather than the customary Na line at 5890)

Uniaxial (—).

Occurrence: In low temperature hydrothermal vein deposits, as an important ore of silver.

Freiburg, Germany; Guadalajara, Spain.

Mexico: Guanajuato and Durango.

Colorado; Idaho; Nevada; California.

Ontario, Canada; Czechoslovakia; Chile.

Colquechaca, Bolivia: fine crystals, gemmy.

Comments: Pyrargyrite is found in a number of localities in well-formed crystals, but these are usually small. However, larger, transparent crystals from Bolivia and Chile have provided a limited amount of cuttable rough. Stones approaching 50 carats have been cut, but these tend to be too dark to be really attractive. They are exceedingly rare, however, since pyrargyrite is seldom transparent, usually even less so than the related sulfide, proustite.

Name: From Greek words meaning fire and silver: in allusion to the color and composition.