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. 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: tetragonal. Typical habit: microscopic crystals.
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(SiAl₂)O₆(OH)₂
- Mohs hardness
- 5-6
- Density
- 2.83 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Tetragonal
- Crystal habit
- Microscopic crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In vesuvianite skarn in a marble, apparently altering from vesuvianite
Where rockhounds find kamaishilite
Classic worldwide localities
- Kamaishi mine, Iwate Prefecture, Japan
Field-hunting tip
Where it forms: In vesuvianite skarn in a marble, apparently altering from vesuvianite. If you start seeing vesuvianite, perovskite, calcite in float, you are in the right ground. Typical habit: microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kamaishilite?+
Where is kamaishilite found?+
What rocks look like kamaishilite?+
What minerals are found with kamaishilite?+
What kind of rock does kamaishilite form in?+
What is kamaishilite used for?+
Find kamaishilite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
