Yarzhemskiite is a rare potassium borate that forms colorless thick tabular, short prismatic or equant crystals. It occurs in a halite-sylvite evaporitic rock in a salt dome. Associated minerals include carnallite, polyhalite and gypsum. It was first described from Chelkar salt dome, near Chelkar lake, Western Kazakhstan, Kazakhstan.
Is this yarzhemskiite?
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 yarzhemskiite with a known reference. Yarzhemskiite sits at Mohs 3, 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: monoclinic. Typical habit: thick tabular, short prismatic or equant crystals.
Often confused with
Yarzhemskiite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside yarzhemskiite
Minerals reported to co-occur with yarzhemskiite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K[B₅O₇(OH)₂]·H₂O
- Mohs hardness
- 3
- Density
- 2.13 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Thick tabular, short prismatic or equant crystals
- Cleavage
- Perfect on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- sedimentary borate deposits
Where rockhounds find yarzhemskiite
Classic worldwide localities
- Inder Borate Deposit, Kazakhstan
Field-hunting tip
Where it forms: sedimentary borate deposits. If you start seeing inderite, halite, gypsum in float, you are in the right ground. Typical habit: thick tabular, short prismatic or equant crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify yarzhemskiite?+
Where is yarzhemskiite found?+
What rocks look like yarzhemskiite?+
What minerals are found with yarzhemskiite?+
What kind of rock does yarzhemskiite form in?+
What is yarzhemskiite used for?+
Find yarzhemskiite on the map
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