Kelyanite is an extremely rare mercury-antimony oxychloride mineral known primarily from its type locality in Russia. It typically forms as thin, yellow platy crystals or granular crusts within mercury-rich hydrothermal ore zones.

Hardness

3.5

Mohs

Luster

Adamantine

Streak

Yellow

Transparency

Translucent

mineralrareMineral Group family

Kelyanite

Hardness: 3.5
Luster: Adamantine
Streak: Yellow
Transparency: Translucent

Is this kelyanite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch kelyanite with a known reference. Kelyanite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Kelyanite leaves a yellow streak.
3
Read the luster
Hold the specimen under a strong light. Kelyanite typically shows a adamantine luster.
4
Match the color range
Compare against the expected color range: yellow, yellow-orange.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: platy or granular.

Often confused with

Kelyanite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Kelyanite is noticeably harder (Mohs 3.5 vs. 2.5); streak differs — Kelyanite leaves yellow, Eglestonite leaves yellowish-white.

Compare →

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: Hg₂SbO₃Cl
Mohs hardness: 3.5
Density: 6.1 g/cm³
Colors: Yellow Yellow-orange
Streak: Yellow
Luster: Adamantine
Transparency: Translucent
Crystal system: Orthorhombic
Crystal habit: Platy or Granular
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Mercury Deposits
Typical price: $100-500 thumbnail

Where rockhounds find kelyanite

Classic worldwide localities

Kelyana mercury deposit, Eastern Sayan Mountains, Russia

Field-hunting tip

Look in hydrothermal mercury deposits country — that is the host setting where kelyanite typically forms. If you start seeing cinnabar, calomel, montroydite in float, you are in the right ground. Field specimens usually show a platy or granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kelyanite?+

Mohs hardness is 3.5. It typically shows a adamantine luster. The streak is yellow. Common colors include yellow, yellow-orange.

Where is kelyanite found?+

Notable localities include Kelyana mercury deposit, Eastern Sayan Mountains, Russia.

How much is kelyanite worth?+

Typical asking prices fall in the range of $100-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

Is kelyanite safe to handle?+

It contains toxic constituents. Contains mercury and antimony; handle with care and wash hands thoroughly after contact. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like kelyanite?+

Kelyanite is most often confused with Terlinguaite, Eglestonite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with kelyanite?+

Kelyanite commonly co-occurs with cinnabar, calomel, montroydite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kelyanite form in?+

Kelyanite typically forms in hydrothermal mercury deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kelyanite used for?+

Kelyanite is used in collector.

Find kelyanite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.