Chelkarite is a rare borate mineral found in the salt deposits of the Chelkar salt dome in Kazakhstan. It typically occurs as small, delicate acicular crystals or fibrous aggregates and is highly prized by mineral collectors due to its extreme scarcity and localized occurrence.
Is this chelkarite?
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 chelkarite with a known reference. Chelkarite sits at Mohs 3-4, 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: colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular crystals, fibrous, prismatic.
Often confused with
Chelkarite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside chelkarite
Minerals reported to co-occur with chelkarite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaMgB₂O₄Cl₂·7H₂O
- Mohs hardness
- 3-4
- Density
- 2.21 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular crystals, fibrous, prismatic
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rare, in the insoluble residue of brines from a salt dome
Where rockhounds find chelkarite
Classic worldwide localities
- Chelkar salt dome, Ak-saı̆ Valley, Uralsk district, Kazakhstan
Field-hunting tip
Where it forms: Very rare, in the insoluble residue of brines from a salt dome. If you start seeing anhydrite, hilgardite, boracite in float, you are in the right ground. Typical habit: acicular crystals, fibrous, prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify chelkarite?+
Where is chelkarite found?+
What rocks look like chelkarite?+
What minerals are found with chelkarite?+
What kind of rock does chelkarite form in?+
What is chelkarite used for?+
Find chelkarite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
