Kolskyite is a rare titanium-niobium silicate mineral primarily found in the hyperalkaline complexes of the Kola Peninsula. It typically occurs as brown, platy tabular crystals embedded within pegmatite matrices, often requiring careful microscopic identification due to its close relationship with the lomonosovite group.

Hardness

3-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareLomonosovite Group family

Kolskyite

Hardness: 3-4
Luster: Vitreous
Streak: White
Transparency: Translucent

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Is this kolskyite?

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

Often confused with

Kolskyite 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 — Kolskyite leaves white, Lomonosovite leaves yellowish brown.

How to tell apart: Luster reads vitreous on Kolskyite and pearly on Murmanite.

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Often found alongside kolskyite

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

All properties

Chemical formula: (Na,Ca)₇(Ti,Nb)₄(Si₂O₇)₂O₄(OH,F)·n(H₂O)
Mohs hardness: 3-4
Density: 2.88 g/cm³
Colors: Brown Yellowish-brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Platy Crystals, Tabular Aggregates
Cleavage: Perfect On {001}
Rarity: Rare
Uses: Collector
Host rock: Alkaline Igneous Rocks, Specifically Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find kolskyite

Classic worldwide localities

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

Field-hunting tip

Look in alkaline igneous rocks, specifically pegmatites country — that is the host setting where kolskyite typically forms. If you start seeing nepheline, microcline, aegirine in float, you are in the right ground. Field specimens usually show a platy crystals, tabular aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify kolskyite?+

Mohs hardness is 3-4. It typically shows a vitreous luster. The streak is white. Common colors include brown, yellowish-brown.

Where is kolskyite found?+

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

How much is kolskyite 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.

What rocks look like kolskyite?+

Kolskyite 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 kolskyite?+

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

What kind of rock does kolskyite form in?+

Kolskyite typically forms in alkaline igneous rocks, specifically pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kolskyite used for?+

Kolskyite is used in collector.

Find kolskyite on the map

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