Kurgantaite is a rare strontium borate mineral found in evaporite basins. Collectors should look for its characteristic tabular crystal habit or massive, granular white aggregates in salt-bearing sequences.
Is this kurgantaite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch kurgantaite with a known reference. Kurgantaite sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: triclinic. Typical habit: nodular, spherical.
Often confused with
Kurgantaite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside kurgantaite
Minerals reported to co-occur with kurgantaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaSrB₅O₉Cl·H₂O
- Mohs hardness
- 6-6.5
- Density
- 2.99 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Nodular, spherical
- Cleavage
- Present in two directions
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In marine evaporite salt deposits and salt domes
Where rockhounds find kurgantaite
Classic worldwide localities
- Western Kargan-tau, Inder uplift and from Chelkar, Caspian region, Kazakhstan, Russia
- Nepskoye potassium salt deposit, near Ust’-Kut, Irkutsk district, Siberia, Russia
- Penobsquis evaporite deposits, 12 km NE of Sussex, New Brunswick, Canada
Field-hunting tip
Where it forms: In marine evaporite salt deposits and salt domes. If you start seeing sylvite, halite, boracite in float, you are in the right ground. Typical habit: nodular, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
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Find kurgantaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
