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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: milky white.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: hexagonal, microscopic crystals, platy.
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
- Ca₃Ge(SO₄)(CO₃)(OH)₆·12H₂O
- Mohs hardness
- 2.5
- Density
- 1.979 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Hexagonal
- Crystal habit
- Hexagonal, microscopic crystals, platy
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral formed by late-stage hydrothermal alteration of earlier sulfides and sulfosalts
Where rockhounds find carraraite
Classic worldwide localities
- Gioia quarry, Colonnata Valley, northeast of Carrara, Tuscany, Italy
Field-hunting tip
Where it forms: A rare secondary mineral formed by late-stage hydrothermal alteration of earlier sulfides and sulfosalts. If you start seeing nordstrandite, dawsonite in float, you are in the right ground. Typical habit: hexagonal, microscopic crystals, platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify carraraite?+
Where is carraraite found?+
What rocks look like carraraite?+
What minerals are found with carraraite?+
What kind of rock does carraraite form in?+
What is carraraite used for?+
Find carraraite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
