Billingsleyite is a rare silver arsenic sulfide mineral that typically occurs as small, metallic grains within hydrothermal ore deposits. It is best identified through laboratory methods like X-ray diffraction or microprobe analysis because it is visually similar to several other complex silver sulfosalts. It is primarily sought after by advanced collectors of rare minerals and silver species.
Is this billingsleyite?
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 billingsleyite with a known reference. Billingsleyite 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. Billingsleyite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Billingsleyite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: silver-white, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, granular, or fine-grained aggregates.
Often confused with
Billingsleyite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside billingsleyite
Minerals reported to co-occur with billingsleyite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ag₇AsS₆
- Mohs hardness
- 2.5
- Density
- 6.9 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Massive, Granular, Or Fine-grained Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Silver-lead Veins
- Typical price
- $50-500 thumbnail, depending on quality
Where rockhounds find billingsleyite
Classic worldwide localities
- Hilltop mine, San Bernardino County, California, USA
Field-hunting tip
Look in hydrothermal silver-lead veins country — that is the host setting where billingsleyite typically forms. If you start seeing arsenopyrite, galena, sphalerite in float, you are in the right ground. Field specimens usually show a massive, granular, or fine-grained aggregates habit, so train your eye for that shape before scanning the outcrop.







