Double Terminated Ruby Red Proustite Floater
Silver Arsenic Sulfide, Ag3AsS3
Crystal System: Trigonal
- Proustite occurs as a late-stage mineral found in hydrothermal veins of low temperature
origin with other silver sulfosalts. It is associated with pyrargyrite in silver veins.
Proustite and pyrargyrite are known as ruby silver ores.
Proustite crystals are usually massive and shiny dark red. They occur less commonly as
striated rhombohedral or scalenohedral crystals which are often distorted and twinned.
Transparent crystals are affected by exposure to light which may cause them to darken
and become opaque.
- Stuart provides the following remarks:
- "This is a very important single double terminated floater Proustite crystal from Chile.
It is from the collection of the 19th century mineralogist George J. Brush. He was the
Curator of the mineral collection at Yale University during the 1870's. This crystal is
very fine because it retains its original gemmy "ruby" red transparency even though it
has been out of the ground for over 100 years. Don't worry, I keep it in the dark at
Rocks from Stuart Wilensky's Collection
Index of Specimen Images
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