Calciocopiapite is a rare sulfate mineral typically found as a secondary oxidation product in sulfide-bearing mining environments. Collectors should look for delicate yellow, platy crystals or efflorescent crusts forming in dry, sheltered areas of mine adits where iron-rich waters have evaporated.
Is this calciocopiapite?
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 calciocopiapite with a known reference. Calciocopiapite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow white.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly.
- 4Match the color rangeCompare against the expected color range: brownish yellow, grayish yellow.
- 5Look at form & habitCrystal system: triclinic. Typical habit: platy crystals, granular crusts, efflorescent coatings.
Often confused with
Calciocopiapite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Calciocopiapite leaves yellow white, Copiapite leaves pale yellow.
How to tell apart: Streak differs, so Calciocopiapite leaves yellow white, Jarosite leaves pale yellow; luster reads pearly on Calciocopiapite and subadamantine to vitreous, resinous on fractures on Jarosite.
How to tell apart: Streak differs, so Calciocopiapite leaves yellow white, Melanterite leaves white; luster reads pearly on Calciocopiapite and vitreous on Melanterite.
Often found alongside calciocopiapite
Minerals reported to co-occur with calciocopiapite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaFe₄(SO₄)₆(OH)₂·20H₂O
- Mohs hardness
- 2.5-3
- Density
- 2.22 g/cm³
- Streak
- Yellow white
- Luster
- Pearly
- Transparency
- Semitransparent
- Crystal system
- Triclinic
- Crystal habit
- Platy crystals, granular crusts, efflorescent coatings
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidized weathering zone of a magnetite–pyrite deposit
Where rockhounds find calciocopiapite
Classic worldwide localities
- Dashkesan deposit, Middle Caucasus Mountains, Azerbaijan
Field-hunting tip
Where it forms: In the oxidized weathering zone of a magnetite–pyrite deposit. If you start seeing chalcanthite, malachite, hydrous iron oxides in float, you are in the right ground. Typical habit: platy crystals, granular crusts, efflorescent coatings. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify calciocopiapite?+
Where is calciocopiapite found?+
What rocks look like calciocopiapite?+
What minerals are found with calciocopiapite?+
What kind of rock does calciocopiapite form in?+
What is calciocopiapite used for?+
Find calciocopiapite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
