Cassedanneite is an exceptionally rare lead vanadate-chromate mineral typically found as small, bright orange prismatic crystals. It is primarily known from its type locality at the Berezovskoe gold deposit in Russia, often appearing as an overgrowth or association with crocoite.
Is this cassedanneite?
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 cassedanneite with a known reference. Cassedanneite 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: yellow-orange.
- 3Read the lusterHold the specimen under a strong light. Luster: resinous.
- 4Match the color rangeCompare against the expected color range: red orange.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: microscopic crystals, platy.
Often confused with
Cassedanneite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads resinous on Cassedanneite and adamantine on Crocoite.
How to tell apart: Streak differs, so Cassedanneite leaves yellow-orange, Vauquelinite leaves greenish to brownish; luster reads resinous on Cassedanneite and adamantine to resinous on Vauquelinite.
Often found alongside cassedanneite
Minerals reported to co-occur with cassedanneite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₅(VO₄)₂(CrO₄)₂·H₂O
- Mohs hardness
- ~3.5
- Density
- 6.37 g/cm³
- Colors
- Streak
- Yellow-orange
- Luster
- Resinous
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Microscopic crystals, platy
- Cleavage
- Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- On museum samples from the oxidized zone of gold-bearing quartz veins (Beresovsk, Russia)
Where rockhounds find cassedanneite
Classic worldwide localities
- Beresovsk, near Yekaterinburg (Sverdlovsk), Middle Ural Mountains, Russia
Field-hunting tip
Where it forms: On museum samples from the oxidized zone of gold-bearing quartz veins (Beresovsk, Russia). If you start seeing crocoite, embreyite, vauquelinite in float, you are in the right ground. Typical habit: microscopic crystals, platy. Train your eye for that shape before scanning the outcrop.
Common questions
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Find cassedanneite on the map
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