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, so Smirnovskite leaves yellowish-white, Monazite leaves white.

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

Compare →

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, 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.