Bambollaite is an extremely rare copper selenium oxysalt mineral that occurs as small, dark blue, platy crystals. It is primarily found in the oxidized zones of selenium-rich hydrothermal deposits, most notably at its type locality in Sonora, Mexico.
Is this bambollaite?
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 bambollaite with a known reference. Bambollaite 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. Streak: blue.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: brownish gray, gray.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: platy crystals, granular aggregates.
Often confused with
Bambollaite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Bambollaite leaves blue, Chalcomenite leaves light blue; luster reads metallic on Bambollaite and vitreous on Chalcomenite.
How to tell apart: Streak differs, so Bambollaite leaves blue, Ahlfeldite leaves light green; luster reads metallic on Bambollaite and vitreous on Ahlfeldite.
Often found alongside bambollaite
Minerals reported to co-occur with bambollaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu(Se,Te)₂
- Mohs hardness
- 3
- Density
- 5.64 g/cm³
- Colors
- Streak
- Blue
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Platy crystals, granular aggregates
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In oxidized Au–Te ore in subparallel quartz veins in a hydrothermally altered tuff
Where rockhounds find bambollaite
Classic worldwide localities
- Moctezuma (Bambolla) mine, 12 km south of Moctezuma, Sonora, Mexico (type locality)
Field-hunting tip
Where it forms: In oxidized Au–Te ore in subparallel quartz veins in a hydrothermally altered tuff. If you start seeing klockmannite, tellurium, selenium in float, you are in the right ground. Typical habit: platy crystals, granular aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify bambollaite?+
Where is bambollaite found?+
Is bambollaite safe to handle?+
What rocks look like bambollaite?+
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Find bambollaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
