Smirnovskite is a rare radioactive phosphate-silicate mineral typically found as resinous, yellow to brown massive aggregates. It is primarily identified through its association with specific pegmatite environments and its significant thorium content.

Hardness

4-5

Mohs

Luster

Resinous

Streak

Yellowish-white

Transparency

Translucent

mineralrareThorium-bearing minerals family

Smirnovskite

Hardness: 4-5
Luster: Resinous
Streak: Yellowish-white
Transparency: Translucent

No image

Is this smirnovskite?

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 smirnovskite with a known reference. Smirnovskite sits at Mohs 4-5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Smirnovskite leaves a yellowish-white streak.
3
Read the luster
Hold the specimen under a strong light. Smirnovskite typically shows a resinous luster.
4
Match the color range
Compare against the expected color range: yellow, brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: massive, aggregates.

Often confused with

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

mineral

Monazite

Mohs 5-5.5

How to tell apart: Streak differs — Smirnovskite leaves yellowish-white, Monazite leaves white.

How to tell apart: Streak differs — Smirnovskite leaves yellowish-white, Thorite leaves dark brown.

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Often found alongside smirnovskite

Minerals reported to co-occur with smirnovskite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: (Th,Ca,Ce)₂(P,Si)O₄(OH,F)·nH₂O
Mohs hardness: 4-5
Density: 4.8-5.0 g/cm³
Colors: Yellow Brown
Streak: Yellowish-white
Luster: Resinous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Massive, Aggregates
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find smirnovskite

Classic worldwide localities

Eastern Siberia, Russia
Transbaikalia, Russia

Field-hunting tip

Look in granite pegmatites country — that is the host setting where smirnovskite typically forms. If you start seeing quartz, feldspar, mica in float, you are in the right ground. Field specimens usually show a massive, aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify smirnovskite?+

Mohs hardness is 4-5. It typically shows a resinous luster. The streak is yellowish-white. Common colors include yellow, brown.

Where is smirnovskite found?+

Notable localities include Eastern Siberia, Russia; Transbaikalia, Russia.

How much is smirnovskite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is smirnovskite safe to handle?+

This mineral is radioactive. Smirnovskite contains thorium and is significantly radioactive; handle with care, store in a lead-lined container, and avoid ingestion or inhalation of dust. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like smirnovskite?+

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

What minerals are found with smirnovskite?+

Smirnovskite commonly co-occurs with Quartz, Feldspar, Mica. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does smirnovskite form in?+

Smirnovskite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is smirnovskite used for?+

Smirnovskite is used in collector.

Find smirnovskite on the map

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