Bismutite is a secondary mineral that typically forms as an oxidation product of native bismuth or bismuthinite. It is most commonly found as earthy, yellowish to white crusts or coatings, making identification often reliant on chemical tests or location context rather than distinct crystal forms.
Is this bismutite?
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 bismutite with a known reference. Bismutite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Bismutite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Bismutite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: yellow, gray, white, green.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: earthy, fibrous, or massive encrustations.
Often confused with
Bismutite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside bismutite
Minerals reported to co-occur with bismutite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Bi₂O₂CO₃
- Mohs hardness
- 3
- Density
- 7.4 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Earthy, Fibrous, Or Massive Encrustations
- Cleavage
- Perfect
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Oxidized Zones of Bismuth-bearing Hydrothermal Veins
- Typical price
- $10-50 per specimen
Where rockhounds find bismutite
4 mapped spotsClassic worldwide localities
- Saxony, Germany
- Cornwall, England
- Bolivia
- South Dakota, USA
Field-hunting tip
Look in oxidized zones of bismuth-bearing hydrothermal veins country — that is the host setting where bismutite typically forms. If you start seeing bismuthinite, native bismuth, quartz in float, you are in the right ground. Field specimens usually show a earthy, fibrous, or massive encrustations habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Colorado, Utah, Wyoming — start trip planning there.
Common questions
How do you identify bismutite?+
Where is bismutite found?+
Can I find bismutite in the United States?+
How much is bismutite worth?+
What rocks look like bismutite?+
What minerals are found with bismutite?+
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Find bismutite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
