Bahianite is an exceptionally rare aluminum antimony mineral found primarily in the diamond-bearing gravels of the Bahia state in Brazil. It is highly valued by collectors and lapidaries for its extreme hardness, which rivals that of chrysoberyl, and its vibrant yellow to brownish-yellow color.
Is this bahianite?
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 bahianite with a known reference. Bahianite sits at Mohs 9, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: colorless, violet, cream white, light brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: equant to prismatic crystals.
Often confused with
Bahianite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads adamantine on Bahianite and vitreous on Chrysoberyl.
How to tell apart: Streak differs, so Bahianite leaves white, Sapphire leaves colorless; luster reads adamantine on Bahianite and vitreous on Sapphire.
Often found alongside bahianite
Minerals reported to co-occur with bahianite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₅Sb₃O₁₄(OH)₂
- Mohs hardness
- 9
- Density
- 4.78-5.29 g/cm³
- Streak
- White
- Luster
- Adamantine
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Equant to prismatic crystals
- Cleavage
- {100}, perfect
- Rarity
- Rare
- Uses
- Collector, Gemstone
- Host rock
- In potholes as stream-worn pebbles and as residual concentrates above weathered volcanic rock
Where rockhounds find bahianite
Classic worldwide localities
- Eight km southeast of the village of Paramirim das Crioulas, in the region around Rio do Picos das Almas, Serra das Almas, south-central Bahia, Brazil
Field-hunting tip
Where it forms: In potholes as stream-worn pebbles and as residual concentrates above weathered volcanic rock. If you start seeing quartz, andalusite, kyanite in float, you are in the right ground. Typical habit: equant to prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify bahianite?+
Where is bahianite found?+
Is bahianite safe to handle?+
What rocks look like bahianite?+
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Find bahianite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
