Rusinovite is an extremely rare calcium silicate chloride mineral discovered in the Chegem volcanic caldera in Russia. It typically occurs as small tabular crystals within high-temperature skarn environments associated with carbonate-rich volcanic xenoliths.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrarenull family

Rusinovite

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

Is this rusinovite?

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 rusinovite with a known reference. Rusinovite sits at Mohs 5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Rusinovite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Rusinovite 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: monoclinic. Typical habit: tabular crystals.

Often confused with

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

How to tell apart: Larnite is the harder of the two (Mohs 6 vs. 5).

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Often found alongside rusinovite

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

All properties

Chemical formula: Ca₇(Si₂O₇)₂Cl₂
Mohs hardness: 5
Density: 3.17 g/cm³
Colors: Yellow Brown Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Skarn
Typical price: $50-300 per specimen

Where rockhounds find rusinovite

Classic worldwide localities

Chegem caldera, Kabardino-Balkaria, Russia

Field-hunting tip

Look in skarn country — that is the host setting where rusinovite typically forms. If you start seeing wadalite, fluorapatite, perovskite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify rusinovite?+

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

Where is rusinovite found?+

Notable localities include Chegem caldera, Kabardino-Balkaria, Russia.

How much is rusinovite 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 rusinovite?+

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

What minerals are found with rusinovite?+

Rusinovite commonly co-occurs with Wadalite, Fluorapatite, Perovskite, Ternesite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does rusinovite form in?+

Rusinovite typically forms in skarn. Working float back to the host body is the standard way to chase a fresh occurrence.

What is rusinovite used for?+

Rusinovite is used in collector.

Find rusinovite on the map

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