Felsőbányaite is a rare secondary sulfate mineral typically found as pearly white crusts or delicate platy aggregates within mine workings. It forms through the alteration of aluminum-bearing minerals in sulfide deposits and is highly prized by collectors for its fragile, tabular crystal habits.
Is this felsőbányaite?
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 felsőbányaite with a known reference. Felsőbányaite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Felsőbányaite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Felsőbányaite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, pale yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, tabular aggregates, pearly flakes.
Often confused with
Felsőbányaite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside felsőbányaite
Minerals reported to co-occur with felsőbányaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₄SO₄(OH)₁₀·4H₂O
- Mohs hardness
- 2
- Density
- 2.16 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Tabular Aggregates, Pearly Flakes
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins in Mines
- Typical price
- $20-100 for small specimens
Where rockhounds find felsőbányaite
Classic worldwide localities
- Baia Sprie, Romania
- Bisbee, Arizona, USA
- Germany
- Poland
Field-hunting tip
Look in hydrothermal veins in mines country, the host setting where felsőbányaite typically forms. If you start seeing gypsum, alunite, pyrite in float, you are in the right ground. Field specimens usually show a platy crystals, tabular aggregates, pearly flakes habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify felsőbányaite?+
Where is felsőbányaite found?+
How much is felsőbányaite worth?+
What rocks look like felsőbányaite?+
What minerals are found with felsőbányaite?+
What kind of rock does felsőbányaite form in?+
What is felsőbányaite used for?+
Find felsőbányaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
