Kelyanite is an extremely rare mercury-antimony oxychloride mineral known primarily from its type locality in Russia. It typically forms as thin, reddish brown platy crystals or granular crusts within mercury-rich hydrothermal ore zones.
Is this kelyanite?
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 kelyanite with a known reference. Kelyanite sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: resinous to vitreous.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: reddish brown, brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: granular.
Often confused with
Kelyanite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Kelyanite leaves resinous to vitreous, Terlinguaite leaves lemon-yellow, turning olive-green; luster reads adamantine on Kelyanite and brilliant adamantine on Terlinguaite.
How to tell apart: Streak differs, so Kelyanite leaves resinous to vitreous, Eglestonite leaves yellow or greenish yellow, rapidly becoming black; luster reads adamantine on Kelyanite and brilliant adamantine to resinous on Eglestonite.
Often found alongside kelyanite
Minerals reported to co-occur with kelyanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Hg₂)₆SbO₆BrCl₂
- Mohs hardness
- 3-3.5
- Density
- 8.51-8.63 g/cm³
- Colors
- Streak
- Resinous to vitreous
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the oxidation zone of a stibnite-cinnabar ore deposit
Where rockhounds find kelyanite
Classic worldwide localities
- Kelyana Sb-Hg mine, North Muya Range, Buryatia, Transbaikal region, Siberia, Russia
Field-hunting tip
Where it forms: In the oxidation zone of a stibnite-cinnabar ore deposit. If you start seeing calomel, eglestonite, mercury in float, you are in the right ground. Typical habit: granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kelyanite?+
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Is kelyanite safe to handle?+
What rocks look like kelyanite?+
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Find kelyanite on the map
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