Yaroslavite is a very rare calcium aluminum fluoride hydroxide mineral. It typically occurs as small tabular crystals or massive grains within hydrothermal vein deposits and is highly prized by advanced mineral collectors for its scarcity.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Yaroslavite

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

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Is this yaroslavite?

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

Often confused with

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

How to tell apart: Yaroslavite is noticeably harder (Mohs 4 vs. 2.5-3); luster reads vitreous on Yaroslavite and vitreous to greasy on Cryolite.

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Often found alongside yaroslavite

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

All properties

Chemical formula: CaCaAlF₆(OH)₂
Mohs hardness: 4
Density: 3.31 g/cm³
Colors: Colorless White Gray
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular Crystals, Massive, Granular Aggregates
Cleavage: Good in One Direction
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find yaroslavite

Classic worldwide localities

Konevo, Russia
Urals, Russia

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where yaroslavite typically forms. If you start seeing fluorite, quartz, calcite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify yaroslavite?+

Mohs hardness is 4. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, gray.

Where is yaroslavite found?+

Notable localities include Konevo, Russia; Urals, Russia.

How much is yaroslavite 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 yaroslavite?+

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

What minerals are found with yaroslavite?+

Yaroslavite commonly co-occurs with Fluorite, Quartz, Calcite, Topaz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does yaroslavite form in?+

Yaroslavite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is yaroslavite used for?+

Yaroslavite is used in collector.

Find yaroslavite on the map

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