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. Tazieffite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Tazieffite typically shows a metallic luster.
- 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
- Fumarolic Encrustations
Where rockhounds find tazieffite
Classic worldwide localities
- Mutnovsky volcano, Far East Asia, Russia
Field-hunting tip
Look in fumarolic encrustations country, the host setting where tazieffite typically forms. If you start seeing galena, pyrite, anglesite in float, you are in the right ground. Field specimens usually show a needle-shaped crystals habit, so 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?+
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Find tazieffite on the map
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