Okenite is famous for its distinct, fuzzy-looking white spheres that resemble cotton balls. These delicate, needle-like crystals are commonly found inside basalt geodes in India, often associated with other zeolites and apophyllite.
Is this okenite?
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 okenite with a known reference. Okenite sits at Mohs 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 to pearly.
- 4Match the color rangeCompare against the expected color range: white, yellowish white, bluish white.
- 5Look at form & habitCrystal system: triclinic. Typical habit: capillary, fibrous, spherical.
Often confused with
Okenite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside okenite
Minerals reported to co-occur with okenite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₁₀Si₁₈O₄₆·18H₂O
- Mohs hardness
- 5
- Density
- 2.28-2.33 g/cm³
- Streak
- White
- Luster
- Vitreous to pearly
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Capillary, fibrous, spherical
- Cleavage
- Perfect on {001}
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Commonly in amygdules in basalts
Where rockhounds find okenite
Classic worldwide localities
- Crestmore, Riverside Co., California, USA
- Fairfax quarry, Centreville, Fairfax Co., Virginia, USA
- Skookumchuck Dam, near Bucoda, Thurston Co., Washington, USA
- Qutdligssat (Kudlisat), Ritenbenk district, Greenland
- Bordoy and Streymoy, Faeroe Islands
- Scawt Hill, near Larne, Co. Antrim, Ireland
Field-hunting tip
Where it forms: Commonly in amygdules in basalts. If you start seeing zeolites, apophyllite, prehnite in float, you are in the right ground. Typical habit: capillary, fibrous, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify okenite?+
Where is okenite found?+
What rocks look like okenite?+
What minerals are found with okenite?+
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Find okenite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
