Slavíkite is a rare hydrated iron-magnesium sulfate typically found as bright yellow to yellow-green crusts or botryoidal coatings. It commonly forms as a secondary mineral in the oxidation zones of sulfide ore deposits, often associated with other iron sulfates.
Is this slavíkite?
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 slavíkite with a known reference. Slavíkite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale yellowish green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: yellowish green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: crystalline, encrustations, granular.
Often confused with
Slavíkite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside slavíkite
Minerals reported to co-occur with slavíkite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (H₃O)₃Mg₆Fe₁₅(SO₄)₂₁(OH)₁₈·98H₂O
- Mohs hardness
- 3.5
- Density
- 1.905-1.99 g/cm³
- Colors
- Streak
- Pale yellowish green
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Crystalline, encrustations, granular
- Cleavage
- On {0001}, a parting
- Rarity
- Rare
- Uses
- Collector
- Host rock
- An uncommon secondary oxidation product of pyrite in shales and slates
Where rockhounds find slavíkite
Classic worldwide localities
- Alum Cave Bluff, Sevier Co., Tennessee, USA
- Valachov Hill, near Skřivaň, Czech Republic
- Troja, near Prague, Czech Republic
- Mandát, Czech Republic
- Medzev, 26 km west of Košice, Slovakia
- Rudabánya, Hungary
Field-hunting tip
Where it forms: An uncommon secondary oxidation product of pyrite in shales and slates. If you start seeing halotrichite, pickeringite, fibroferrite in float, you are in the right ground. Typical habit: crystalline, encrustations, granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify slavíkite?+
Where is slavíkite found?+
What rocks look like slavíkite?+
What minerals are found with slavíkite?+
What kind of rock does slavíkite form in?+
What is slavíkite used for?+
Find slavíkite on the map
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