Sobolevite is an extremely rare silicate mineral found in the hyper-alkaline environments of the Kola Peninsula. It typically occurs as small tabular crystals or granular masses within highly evolved pegmatitic pockets alongside complex accessory minerals.

Hardness

4-5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Sobolevite

Hardness: 4-5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this sobolevite?

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 sobolevite with a known reference. Sobolevite 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. Sobolevite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Sobolevite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown, colorless.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, massive, granular.

Often confused with

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

mineral

Lomonosovite

Mohs 3-4

How to tell apart: Streak differs, so Sobolevite leaves white, Lomonosovite leaves yellowish brown.

How to tell apart: Sobolevite is noticeably harder (Mohs 4-5 vs. 2-3); luster reads vitreous on Sobolevite and pearly on Murmanite.

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Often found alongside sobolevite

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

All properties

Chemical formula: Na₁₄Ca₂MgMnTi₂Si₈O₃₄F₂
Mohs hardness: 4-5
Density: 2.81 g/cm³
Colors: Yellow Brown Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Triclinic
Crystal habit: Tabular Crystals, Massive, Granular
Cleavage: Good On {001}
Rarity: Rare
Uses: Collector
Host rock: Alkaline Pegmatites
Typical price: expensive for rare mineral species

Where rockhounds find sobolevite

Classic worldwide localities

Khibiny Massif, Kola Peninsula, Russia
Lovozero Massif, Kola Peninsula, Russia

Field-hunting tip

Look in alkaline pegmatites country, the host setting where sobolevite typically forms. If you start seeing nepheline, aegirine, eudialyte in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify sobolevite?+

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

Where is sobolevite found?+

Notable localities include Khibiny Massif, Kola Peninsula, Russia; Lovozero Massif, Kola Peninsula, Russia.

How much is sobolevite worth?+

Typical asking prices fall in the range of expensive for rare mineral species. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like sobolevite?+

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

What minerals are found with sobolevite?+

Sobolevite commonly co-occurs with Nepheline, Aegirine, Eudialyte, Microcline, Lomonosovite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does sobolevite form in?+

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

What is sobolevite used for?+

Sobolevite is used in collector.

Find sobolevite on the map

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