Scolecite is a beautiful member of the zeolite group, prized by collectors for its stunning, delicate, needle-like crystals that often form large, radiating white sprays. It is most frequently found filling amygdules in basaltic rocks, particularly in the Deccan Traps region of India. Collectors should handle specimens with care due to the fragile nature of the acicular clusters.
Is this scolecite?
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 scolecite with a known reference. Scolecite sits at Mohs 5-5.5, 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, silky when fibrous.
- 4Match the color rangeCompare against the expected color range: white, colorless, pink, salmon, brownish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive, radial.
Often confused with
Scolecite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside scolecite
Minerals reported to co-occur with scolecite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaAl₂Si₃O₁₀·3H₂O
- Mohs hardness
- 5-5.5
- Density
- 2.25-2.29 g/cm³
- Streak
- White
- Luster
- Vitreous, silky when fibrous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Massive, radial
- Cleavage
- {110} and {110}, perfect
- Rarity
- Common
- Uses
- Collector, Specimen
- Host rock
- Primarily in cavities in basalts; in gneisses and amphibolites, and in laccoliths and dikes derived from syenitic and gabbroic magmas
Where rockhounds find scolecite
Classic worldwide localities
- South fork of the Toutle River, Cowlitz Co., in the Pioneer quarry, Bremerton, Kitsap Co., Washington, USA
- Teigarhorn, Berufjord, Iceland
- Ben More, Isle of Mull, and Talisker Bay, Isle of Skye, Scotland
- P°üglhof, Malta Valley, Carinthia, Austria
- Shattig Wichel, Fallital-Giuv area, Graübunden, Switzerland
- Poona, Nasik, and Bombay districts, Maharashtra, India
Field-hunting tip
Where it forms: Primarily in cavities in basalts; in gneisses and amphibolites, and in laccoliths and dikes derived from syenitic and gabbroic magmas. If you start seeing zeolites, prehnite, calcite in float, you are in the right ground. Typical habit: massive, radial. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify scolecite?+
Where is scolecite found?+
What rocks look like scolecite?+
What minerals are found with scolecite?+
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What is scolecite used for?+
Find scolecite on the map
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