Johachidolite is an extremely rare borate mineral that occurs as small, colorless to white crystals. It is primarily found in highly metamorphosed limestone environments and is highly prized by collectors for its exceptional rarity and clarity.
Is this johachidolite?
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 johachidolite with a known reference. Johachidolite sits at Mohs 7.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Johachidolite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Johachidolite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white, yellowish.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular crystals, massive, granular.
Often confused with
Johachidolite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside johachidolite
Minerals reported to co-occur with johachidolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaAlB₃O₇
- Mohs hardness
- 7.5
- Density
- 3.41 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular Crystals, Massive, Granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Lapidary
- Host rock
- Metamorphosed Limestone
- Typical price
- $100-500 per carat for faceted specimens
Where rockhounds find johachidolite
Classic worldwide localities
- Johachido, North Korea
- Mogok, Myanmar
Field-hunting tip
Look in metamorphosed limestone country — that is the host setting where johachidolite typically forms. If you start seeing calcite, phlogopite, spinel in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.






