Tazieffite is a rare lead cadmium arsenic sulfosalt that forms needle-shaped crystals. It is a sublimate at an active volcanic fumarole. It was first described from Mutnovsky volcano, Kamchatka Peninsula, Far East Asia, Russia.
Is this tazieffite?
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 tazieffite with a known reference. Tazieffite 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. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: silvery gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: needle-shaped crystals.
Often confused with
Tazieffite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Tazieffite leaves black, Tellurite leaves white; luster reads metallic on Tazieffite and subadamantine on Tellurite.
How to tell apart: Tazieffite is noticeably harder (Mohs 2 vs. 1); streak differs, so Tazieffite leaves black, Paratellurite leaves white; luster reads metallic on Tazieffite and resinous to waxy on Paratellurite.
Often found alongside tazieffite
Minerals reported to co-occur with tazieffite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂₀Cd₂(As,Bi)₂₂S₅₀Cl₁₀
- Mohs hardness
- 2
- Density
- 6.07 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Needle-shaped crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A sublimate at an active volcanic fumarole
Where rockhounds find tazieffite
Classic worldwide localities
- Mutnovsky volcano, Kamchatka Peninsula, Far East Asia, Russia
Field-hunting tip
Where it forms: A sublimate at an active volcanic fumarole. If you start seeing greenockite, galena, mutnovskite in float, you are in the right ground. Typical habit: needle-shaped crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tazieffite?+
Where is tazieffite found?+
Is tazieffite safe to handle?+
What rocks look like tazieffite?+
What minerals are found with tazieffite?+
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What is tazieffite used for?+
Find tazieffite on the map
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