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. Nekoite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Nekoite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 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.
How to tell apart: Luster reads vitreous on Nekoite and pearly on Okenite.
How to tell apart: Luster reads vitreous on Nekoite and pearly on Gyrolite.
How to tell apart: Nekoite is noticeably harder (Mohs 4.5 vs. 2.5); luster reads vitreous on Nekoite and vitreous to silky on Tobermorite.
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
- 2.26 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Bladed Crystals, Radial Aggregates, Fibrous
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Limestone
Where rockhounds find nekoite
Classic worldwide localities
- Goodsprings, Nevada, USA
- Santa Monica Mountains, California, USA
- Crestmore, California, USA
Field-hunting tip
Look in metamorphosed limestone country, the host setting where nekoite typically forms. If you start seeing apophyllite, calcite, prehnite in float, you are in the right ground. Field specimens usually show a bladed crystals, radial aggregates, fibrous habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nekoite?+
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Find nekoite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
