Clinoptilolite-K is a member of the zeolite group most commonly found in volcanic ash deposits that have been altered by alkaline groundwater. It frequently occurs as small, tabular monoclinic crystals or massive, earthy aggregates and is widely valued in industry for its ion-exchange and molecular sieve properties.
Is this clinoptilolite-k?
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 clinoptilolite-k with a known reference. Clinoptilolite-K 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.
- 4Match the color rangeCompare against the expected color range: white, colorless, red.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: crystalline, tabular.
Often confused with
Clinoptilolite-K vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside clinoptilolite-k
Minerals reported to co-occur with clinoptilolite-k. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₆(Si₃₀Al₆)O₇₂·20H₂O
- Mohs hardness
- 3.5-4
- Density
- 2.1-2.2 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Crystalline, tabular
- Cleavage
- Perfect on {010}
- Fluorescence
- Light green under SW UV
- Rarity
- Common
- Uses
- Industrial, Collector, Filtration
- Host rock
- Most commonly formed as a devitrification product of silicic volcanic glass from tuffs
Where rockhounds find clinoptilolite-k
Classic worldwide localities
- USA
- Japan
- New Zealand
- Iceland
- Italy
Field-hunting tip
Where it forms: Most commonly formed as a devitrification product of silicic volcanic glass from tuffs. If you start seeing quartz, calcite, mordenite in float, you are in the right ground. Typical habit: crystalline, tabular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify clinoptilolite-k?+
Where is clinoptilolite-k found?+
What rocks look like clinoptilolite-k?+
What minerals are found with clinoptilolite-k?+
What kind of rock does clinoptilolite-k form in?+
What is clinoptilolite-k used for?+
Find clinoptilolite-k on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
