Pyrargyrite is a high-grade silver sulfosalt that is prized by collectors for its deep, blood-red internal reflections when viewed under bright light. It typically forms as prismatic to tabular crystals in hydrothermal vein deposits and is often associated with other silver minerals. Because it is light-sensitive and can darken over time with prolonged exposure, it should be stored in a dark environment.
Is this pyrargyrite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch pyrargyrite with a known reference. Pyrargyrite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: purplish red.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: dark red, grayish red, black, deep red, red gray.
- 5Look at form & habitCrystal system: trigonal. Typical habit: crystalline, massive, prismatic.
Often confused with
Pyrargyrite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Pyrargyrite leaves purplish red, Proustite leaves vermilion.
How to tell apart: Streak differs, so Pyrargyrite leaves purplish red, Cinnabar leaves scarlet.
How to tell apart: Streak differs, so Pyrargyrite leaves purplish red, Tetrahedrite leaves black to brown; luster reads adamantine on Pyrargyrite and metallic, commonly splendent on Tetrahedrite.
Often found alongside pyrargyrite
Minerals reported to co-occur with pyrargyrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ag₃SbS₃
- Mohs hardness
- 2.5
- Density
- 5.82 g/cm³
- Streak
- Purplish red
- Luster
- Adamantine
- Transparency
- Translucent, darkens with exposure to light
- Crystal system
- Trigonal
- Crystal habit
- Crystalline, massive, prismatic
- Cleavage
- Distinct on {1011}, very imperfect on {0112}
- Rarity
- Uncommon
- Uses
- Collector, Minor silver ore
- Host rock
- Formed in hydrothermal veins as a primary late-stage, low-temperature mineral; also formed by secondary processes
Where rockhounds find pyrargyrite
2 mapped spotsClassic worldwide localities
- Comstock Lode, Virginia City, Storey Co., in the Hecla Rosebud mine, Rosebud district, Pershing Co., and from the Reese River district, Lander Co., Nevada, USA
- Poorman mine, Silver City district, Owyhee Co., Idaho, USA
- Harz Mountains, at St. Andreasberg, Germany
- Himmelsfürst mine, Erbisdorf, near Freiberg, Saxony, Germany
- Hiendelaencina, Guadalajara Province, Spain
- Jáchymov (Joachimsthal) and from Příbram, Czech Republic
Field-hunting tip
Where it forms: Formed in hydrothermal veins as a primary late-stage, low-temperature mineral; also formed by secondary processes. If you start seeing silver, acanthite, tetrahedrite in float, you are in the right ground. Typical habit: crystalline, massive, prismatic. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Idaho, New Mexico. Start trip planning there.
Common questions
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Find pyrargyrite on the map
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