Aschamalmite is a rare lead-bismuth sulfosalt that occurs primarily in metamorphic environments. It typically forms microscopic lead-gray metallic grains and is usually identified through X-ray diffraction or electron microprobe analysis rather than visual inspection alone.
Is this aschamalmite?
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 aschamalmite with a known reference. Aschamalmite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: lead gray, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: lath, massive.
Often confused with
Aschamalmite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside aschamalmite
Minerals reported to co-occur with aschamalmite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₆Bi₂S₉
- Mohs hardness
- 3.5
- Density
- 7.27 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Lath, massive
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In alpine veins, cutting gneiss
Where rockhounds find aschamalmite
Classic worldwide localities
- Granite Gap, Hidalgo Co., New Mexico, USA
- Ascham Alm, Untersulzbachtal, Salzburg, Austria (type locality)
Field-hunting tip
Where it forms: In alpine veins, cutting gneiss. If you start seeing cosalite, galena, quartz in float, you are in the right ground. Typical habit: lath, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aschamalmite?+
Where is aschamalmite found?+
Is aschamalmite safe to handle?+
What rocks look like aschamalmite?+
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Find aschamalmite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
