Atelestite is a rare secondary bismuth arsenate mineral typically found as small, brilliant yellow-green crystalline crusts or aggregates. It is most famously associated with the historical mining districts of Saxony, where it forms in the oxidation zones of bismuth-rich hydrothermal deposits.
Is this atelestite?
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 atelestite with a known reference. Atelestite sits at Mohs 4.5-5, 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: resinous to adamantine.
- 4Match the color rangeCompare against the expected color range: green, light yellow, black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: microscopic crystals, spherical aggregates, crusts.
Often confused with
Atelestite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Atelestite leaves white, Mixite leaves pale bluish green; luster reads resinous to adamantine on Atelestite and vitreous, silky in aggregates on Mixite.
How to tell apart: Atelestite is noticeably harder (Mohs 4.5-5 vs. 3.5); streak differs, so Atelestite leaves white, Walpurgite leaves pale brownish yellow; luster reads resinous to adamantine on Atelestite and adamantine to greasy on Walpurgite.
Often found alongside atelestite
Minerals reported to co-occur with atelestite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Bi₂O(AsO₄)(OH)
- Mohs hardness
- 4.5-5
- Density
- 7.14 g/cm³
- Colors
- Streak
- White
- Luster
- Resinous to adamantine
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Microscopic crystals, spherical aggregates, crusts
- Cleavage
- {100}, indistinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As a rare secondary mineral in the oxidized zone of bismuth- and arsenic-bearing mineral deposits
Where rockhounds find atelestite
Classic worldwide localities
- Mammoth mine, Tintic district, Juab Co., on Gold Hill, Tooele Co., and from the Northern Spy mine, Utah Co, USA
- Saxony, at the Neuhilfe, the Weisser Hirsch, and the Junge Kalbe mines, Neustädtel-Schneeberg, Germany
- Gadernheim, near Bensheim, Hesse, Germany
- Neubulach and the Schmiedestollen, near Wittichen, Black Forest, Germany
- Smrkovec, Slavkovský Les Mountains, about 10 km north-northeast of Mariánské Lázně (Marienbad), Czech Republic
Field-hunting tip
Where it forms: As a rare secondary mineral in the oxidized zone of bismuth- and arsenic-bearing mineral deposits. If you start seeing bismutite, eulytite, erythrite in float, you are in the right ground. Typical habit: microscopic crystals, spherical aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
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Find atelestite on the map
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