Mrázekite is a highly sought-after secondary copper-bismuth phosphate mineral known for its intense deep blue color and distinctive thin, platy crystals. It typically forms in the oxidized zones of copper deposits where bismuth is present, often appearing as delicate rosettes or sprays on matrix.
Is this mrázekite?
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 mrázekite with a known reference. Mrázekite 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. Streak: blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: blue, cerulean blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic, spherical.
Often confused with
Mrázekite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside mrázekite
Minerals reported to co-occur with mrázekite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Bi₂Cu₃(PO₄)₂O₂(OH)₂·2H₂O
- Mohs hardness
- 2-3
- Density
- 4.90 g/cm³
- Colors
- BlueCerulean blue
- Streak
- Blue
- Luster
- Vitreous
- Transparency
- Translucent to transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic, spherical
- Cleavage
- On {201}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral formed by oxidization of polymetallic sulfides
Where rockhounds find mrázekite
Classic worldwide localities
- L’ubietová, near Baňská Bystrica (Libethen, near Neusohl), Slovakia
- Gadernheim and Reichenbach, near Bensheim, Hesse, Germany
- Sainte-Marie-aux-Mines, Haut-Rhin, France
- Morass Creek Gorge, 15 km north of Benambra, Victoria, Australia
Field-hunting tip
Where it forms: A rare secondary mineral formed by oxidization of polymetallic sulfides. If you start seeing chalcopyrite, tetrahedrite, chalcocite in float, you are in the right ground. Typical habit: prismatic, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mrázekite?+
Where is mrázekite found?+
Is mrázekite safe to handle?+
What rocks look like mrázekite?+
What minerals are found with mrázekite?+
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Find mrázekite on the map
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