Katayamalite is a very rare silicate mineral typically found in nepheline syenites and alkaline igneous complexes. It usually presents as small, pale pink or colorless tabular crystals associated with rare-earth or titanium-bearing minerals.
Is this katayamalite?
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 katayamalite with a known reference. Katayamalite sits at Mohs 3.5-4, 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 to pearly.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular, twinning common.
Often confused with
Katayamalite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside katayamalite
Minerals reported to co-occur with katayamalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KLi₃Ca₇Ti₂(SiO₃)₁₂(OH)₂
- Mohs hardness
- 3.5-4
- Density
- 2.91 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous to pearly
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Tabular, twinning common
- Cleavage
- Perfect on {001}
- Fluorescence
- Bright blue white under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Found in an aegirine syenite
Where rockhounds find katayamalite
Classic worldwide localities
- Iwagi Islet, Ehime Prefecture, Japan (type locality)
Field-hunting tip
Where it forms: Found in an aegirine syenite. If you start seeing aegirine, microcline, nepheline in float, you are in the right ground. Typical habit: tabular, twinning common. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify katayamalite?+
Where is katayamalite found?+
What rocks look like katayamalite?+
What minerals are found with katayamalite?+
What kind of rock does katayamalite form in?+
What is katayamalite used for?+
Find katayamalite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
