Senarmontite is an antimony oxide mineral typically found in the oxidation zones of antimony deposits. It is most commonly identified by its sharp octahedral crystals and high density, often altering to the orthorhombic polymorph valentinite.
Is this senarmontite?
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 senarmontite with a known reference. Senarmontite 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. Senarmontite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Senarmontite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, gray, pale yellow.
- 5Look at form & habitCrystal system: cubic. Typical habit: octahedral crystals, massive, crusts.
Often confused with
Senarmontite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside senarmontite
Minerals reported to co-occur with senarmontite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Sb₂O₃
- Mohs hardness
- 2.5
- Density
- 5.2-5.3 g/cm³
- Streak
- White
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Octahedral Crystals, Massive, Crusts
- Cleavage
- Poor On {111}
- Rarity
- Uncommon
- Uses
- Collector, Minor Ore of Antimony
- Host rock
- Oxidized Zones of Antimony-bearing Hydrothermal Deposits
- Typical price
- $20-150 thumbnail to miniature
Where rockhounds find senarmontite
Classic worldwide localities
- Algeria
- France
- Italy
- Czech Republic
- China
Field-hunting tip
Look in oxidized zones of antimony-bearing hydrothermal deposits country — that is the host setting where senarmontite typically forms. If you start seeing stibnite, valentinite, kermesite in float, you are in the right ground. Field specimens usually show a octahedral crystals, massive, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify senarmontite?+
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How much is senarmontite worth?+
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What rocks look like senarmontite?+
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Find senarmontite on the map
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