Takedaite is a rare borate mineral typically found as small, colorless, tabular crystals within skarn deposits. It is primarily known from the Fuka mine in Japan where it occurs in association with other rare calcium borate and silicate minerals.
Is this takedaite?
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 takedaite with a known reference. Takedaite sits at Mohs 4.5, 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: colorless, white, pale gray.
- 5Look at form & habitCrystal system: trigonal. Typical habit: granular.
Often confused with
Takedaite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside takedaite
Minerals reported to co-occur with takedaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃B₂O₆
- Mohs hardness
- 4.5
- Density
- 3.10 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Trigonal
- Crystal habit
- Granular
- Cleavage
- Imperfect on {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral probably formed by boron-rich fluids reacting between crystalline limestone and gehlenite-spurrite skarns
Where rockhounds find takedaite
Classic worldwide localities
- Fuka, near Bicchu, Okayama Prefecture, Japan
Field-hunting tip
Where it forms: A rare mineral probably formed by boron-rich fluids reacting between crystalline limestone and gehlenite-spurrite skarns. If you start seeing frolovite, nifontovite, olshanskyite in float, you are in the right ground. Typical habit: granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify takedaite?+
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What rocks look like takedaite?+
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Find takedaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
