Kamaishilite is a rare tectosilicate mineral primarily associated with metamorphic skarn environments. It is often found intergrown with other calcium-rich silicates and is recognized by its distinct tetragonal crystal structure, though it is usually identified through laboratory analysis due to its unremarkable macroscopic appearance.
Is this kamaishilite?
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 kamaishilite with a known reference. Kamaishilite sits at Mohs 5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Kamaishilite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Kamaishilite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, pale yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: rarely found in euhedral crystals, typically massive or as granular aggregates in skarn deposits.
Often confused with
Kamaishilite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside kamaishilite
Minerals reported to co-occur with kamaishilite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂(Si₂Al₂O₈)(OH)₂
- Mohs hardness
- 5-6
- Density
- 2.35-2.40 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Tetragonal
- Crystal habit
- Rarely Found in Euhedral Crystals, Typically Massive or as Granular Aggregates in Skarn Deposits
- Cleavage
- Poor
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Skarn Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find kamaishilite
Classic worldwide localities
- Kamaishi mine, Japan
- Potash deposit, Saskatchewan, Canada
Field-hunting tip
Look in skarn deposits country, the host setting where kamaishilite typically forms. If you start seeing calcite, garnet, vesuvianite in float, you are in the right ground. Field specimens usually show a rarely found in euhedral crystals, typically massive or as granular aggregates in skarn deposits habit, so train your eye for that shape before scanning the outcrop.







