Mesolite is a delicate zeolite mineral often found as fine, needle-like acicular crystals or radiating sprays within basalt vesicles. It is visually very similar to natrolite and scolecite, usually requiring lab tests or specific crystal habit analysis to differentiate confidently from its zeolite cousins.
Is this mesolite?
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 mesolite with a known reference. Mesolite 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. Mesolite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Mesolite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular crystals, radiating tufts, fibrous aggregates.
Often confused with
Mesolite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside mesolite
Minerals reported to co-occur with mesolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Ca₂Si₉Al₆O₃₀·8H₂O
- Mohs hardness
- 5
- Density
- 2.26-2.27 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular Crystals, Radiating Tufts, Fibrous Aggregates
- Cleavage
- Perfect
- Rarity
- Uncommon
- Uses
- Collector, Scientific Research
- Host rock
- Basaltic Volcanic Cavities
- Typical price
- $10-100 per specimen
Where rockhounds find mesolite
1 mapped spotsClassic worldwide localities
- Nasik, India
- Iceland
- Faroe Islands
- Pooona, India
- Scotland
Field-hunting tip
Look in basaltic volcanic cavities country — that is the host setting where mesolite typically forms. If you start seeing calcite, apophyllite, heulandite in float, you are in the right ground. Field specimens usually show a acicular crystals, radiating tufts, fibrous aggregates habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Oregon — start trip planning there.






