Bütschliite is a rare potassium calcium carbonate mineral often formed in the heat-altered zones of burning coal seams. It is typically found as small, fragile crystals associated with fairchildite and requires careful handling due to its sensitivity to humidity and moisture.
Is this bütschliite?
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 bütschliite with a known reference. Bütschliite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Bütschliite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Bütschliite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, pale yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals, crusts, aggregates.
Often confused with
Bütschliite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside bütschliite
Minerals reported to co-occur with bütschliite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₂Ca(CO₃)₂
- Mohs hardness
- 2.5
- Density
- 2.16 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular Crystals, Crusts, Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Burning Coal Dumps, Evaporite Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find bütschliite
Classic worldwide localities
- Butch Lake, Saskatchewan, Canada
- Khibiny Massif, Russia
- Hatrurim Formation, Israel
Field-hunting tip
Look in burning coal dumps, evaporite deposits country — that is the host setting where bütschliite typically forms. If you start seeing fairchildite, calcite, nahcolite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts, aggregates habit, so train your eye for that shape before scanning the outcrop.



