Nekoite is a rare calcium silicate mineral typically found in cavities within contact-metamorphosed limestone. Collectors look for its delicate, white, bladed or fibrous crystal clusters that often form radiating spray habits.
Is this nekoite?
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 nekoite with a known reference. Nekoite 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: pearl white.
- 5Look at form & habitCrystal system: triclinic. Typical habit: bladed crystals, radial aggregates, fibrous.
Often confused with
Nekoite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside nekoite
Minerals reported to co-occur with nekoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃Si₆O₁₅·7H₂O
- Mohs hardness
- 4.5
- Density
- 2.21-2.24 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Bladed crystals, radial aggregates, fibrous
- Cleavage
- Distinct on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a contact metamorphosed limestone deposit (Crestmore, California, USA)
Where rockhounds find nekoite
Classic worldwide localities
- Crestmore, Riverside Co., California, and at Landsman's Camp, Aravaipa district, Graham Co., Arizona, USA
- Caxias do Sul, Rio Grande do Sul, Brazil
- Kochbulak deposit, eastern Uzbekistan
Field-hunting tip
Where it forms: In a contact metamorphosed limestone deposit (Crestmore, California, USA). If you start seeing apophyllite, heulandite in float, you are in the right ground. Typical habit: bladed crystals, radial aggregates, fibrous. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nekoite?+
Where is nekoite found?+
What rocks look like nekoite?+
What minerals are found with nekoite?+
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Find nekoite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
