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, so 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, 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.