Carraraite is a very rare calcium sulfate mineral typically found as tiny, delicate acicular white crystals. It is primarily known from the historic marble quarries of Carrara, Italy, where it occurs within cavities in metamorphosed limestone. Due to its extreme rarity and small crystal size, it is a highly sought-after species for advanced mineral collectors.
Is this carraraite?
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 carraraite with a known reference. Carraraite 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. Carraraite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Carraraite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: acicular crystals, radiated aggregates.
Often confused with
Carraraite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside carraraite
Minerals reported to co-occur with carraraite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₄(SO₄)(OH)₈·12H₂O
- Mohs hardness
- 2.5
- Density
- 2.44 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Acicular Crystals, Radiated Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Limestone
- Typical price
- $50-300 per specimen
Where rockhounds find carraraite
Classic worldwide localities
- Carrara, Italy
Field-hunting tip
Look in metamorphosed limestone country — that is the host setting where carraraite typically forms. If you start seeing calcite, gypsum, ettringite in float, you are in the right ground. Field specimens usually show a acicular crystals, radiated aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find carraraite on the map
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