Bianchite is a rare secondary zinc sulfate mineral that typically forms as white, powdery efflorescences or crusts in the oxidized zones of mine workings. Collectors often find it associated with other sulfate minerals in historical zinc mines, though it is highly soluble and requires careful storage away from humidity.
Is this bianchite?
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 bianchite with a known reference. Bianchite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Bianchite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Bianchite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: crusts, efflorescences, granular aggregates.
Often confused with
Bianchite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside bianchite
Minerals reported to co-occur with bianchite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- ZnSO₄·6H₂O
- Mohs hardness
- 2
- Density
- 2.28 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Crusts, Efflorescences, Granular Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Zinc Ore Deposits
- Typical price
- $20-100 for micro-mount specimens
Where rockhounds find bianchite
Classic worldwide localities
- Raibl Mine, Italy
- Lavrion District, Greece
- Broken Hill, Australia
Field-hunting tip
Look in oxidized zones of zinc ore deposits country — that is the host setting where bianchite typically forms. If you start seeing goslarite, sphalerite, gypsum in float, you are in the right ground. Field specimens usually show a crusts, efflorescences, granular aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify bianchite?+
Where is bianchite found?+
How much is bianchite worth?+
What rocks look like bianchite?+
What minerals are found with bianchite?+
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Find bianchite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
