Katerinopoulosite is an extremely rare ammonium-iron sulfate mineral found primarily in the historic mine dumps of the Lavrion District in Greece. It typically forms as delicate, white, acicular crystal sprays or coatings associated with other secondary sulfate minerals in oxidized hydrothermal deposits.
Is this katerinopoulosite?
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 katerinopoulosite with a known reference. Katerinopoulosite sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Katerinopoulosite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Katerinopoulosite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular to fibrous aggregates.
Often confused with
Katerinopoulosite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside katerinopoulosite
Minerals reported to co-occur with katerinopoulosite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (NH₄)₂Fe(SO₄)₂·6H₂O
- Mohs hardness
- 2-3
- Density
- 2.16 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular to Fibrous Aggregates
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Mine Dumps
- Typical price
- $50-300 per specimen
Where rockhounds find katerinopoulosite
Classic worldwide localities
- Lavrion District, Greece
Field-hunting tip
Look in oxidized mine dumps country — that is the host setting where katerinopoulosite typically forms. If you start seeing jarosite, goethite, gypsum in float, you are in the right ground. Field specimens usually show a acicular to fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify katerinopoulosite?+
Where is katerinopoulosite found?+
How much is katerinopoulosite worth?+
What rocks look like katerinopoulosite?+
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What kind of rock does katerinopoulosite form in?+
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Find katerinopoulosite on the map
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