Tatarskite is an exceptionally rare hydrous calcium magnesium sulfate-carbonate-chloride mineral. It typically occurs as small, colorless to white tabular crystals within evaporite sequences and is primarily prized by advanced mineral collectors for its unique chemical composition.

Hardness

2.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Tatarskite

Hardness: 2.5
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this tatarskite?

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 tatarskite with a known reference. Tatarskite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Tatarskite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Tatarskite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular crystals, radiating aggregates.

Often confused with

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

Often found alongside tatarskite

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

All properties

Chemical formula: Ca₃Mg(SO₄)(CO₃)Cl₂(OH)₂·16H₂O
Mohs hardness: 2.5
Density: 1.74 g/cm³
Colors: Colorless White
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular Crystals, Radiating Aggregates
Cleavage: Perfect in One Direction
Rarity: Rare
Uses: Collector
Host rock: Evaporite Deposits
Typical price: $50-300 per specimen

Where rockhounds find tatarskite

Classic worldwide localities

Tatarskoye deposit, Russia
Kayser Mountains, Russia

Field-hunting tip

Look in evaporite deposits country — that is the host setting where tatarskite typically forms. If you start seeing halite, sylvite, carnallite in float, you are in the right ground. Field specimens usually show a tabular crystals, radiating aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tatarskite?+

Mohs hardness is 2.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white.

Where is tatarskite found?+

Notable localities include Tatarskoye deposit, Russia; Kayser Mountains, Russia.

How much is tatarskite 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 tatarskite?+

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

What minerals are found with tatarskite?+

Tatarskite commonly co-occurs with Halite, Sylvite, Carnallite, Gypsum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tatarskite form in?+

Tatarskite typically forms in evaporite deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tatarskite used for?+

Tatarskite is used in collector.

Find tatarskite on the map

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