Kuzminite is an extremely rare mercury halide mineral typically found as fine-grained aggregates in mercury-rich hydrothermal deposits. Due to its chemical composition, it is sensitive to light and should be stored in a dark environment to prevent degradation.
Is this kuzminite?
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 kuzminite with a known reference. Kuzminite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Kuzminite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Kuzminite typically shows a greasy luster.
- 4Match the color rangeCompare against the expected color range: white, gray.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: granular.
Often confused with
Kuzminite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads greasy on Kuzminite and adamantine on Calomel.
How to tell apart: Streak differs, so Kuzminite leaves white, Eglestonite leaves yellowish-white; luster reads greasy on Kuzminite and adamantine on Eglestonite.
Often found alongside kuzminite
Minerals reported to co-occur with kuzminite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Hg₂ClBr
- Mohs hardness
- 2.5
- Density
- 5.68 g/cm³
- Streak
- White
- Luster
- Greasy
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Mercury Deposits
- Typical price
- $100-500+ for micro-specimens
Where rockhounds find kuzminite
Classic worldwide localities
- Kadyrel mercury deposit, Tuva Republic, Russia
Field-hunting tip
Look in hydrothermal mercury deposits country, the host setting where kuzminite typically forms. If you start seeing calomel, cinnabar, mercury in float, you are in the right ground. Field specimens usually show a granular habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find kuzminite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
