Zeophyllite is a rare calcium silicate mineral characterized by its delicate, platy or rosette-like crystal clusters. It is typically found in the cavities of basaltic rocks and is highly prized by collectors for its distinctive pearly luster and soft, pale coloration.
Is this zeophyllite?
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 zeophyllite with a known reference. Zeophyllite sits at Mohs 3, 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: pearly.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: platy, radial, spherical.
Often confused with
Zeophyllite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Apophyllite is the harder of the two (Mohs 4-5 vs. 3); luster reads pearly on Zeophyllite and vitreous to pearly on Apophyllite.
How to tell apart: Luster reads pearly on Zeophyllite and vitreous on Stilbite.
How to tell apart: Luster reads pearly on Zeophyllite and vitreous, pearly on {010} on Heulandite.
Often found alongside zeophyllite
Minerals reported to co-occur with zeophyllite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₁₃Si₁₀O₂₈(OH)₂F₈·6H₂O
- Mohs hardness
- 3
- Density
- 2.747-2.764 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Platy, radial, spherical
- Cleavage
- {0001}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In cavities, as a secondary mineral from hydrothermal alteration of basalt (Litoměřice, Czech Republic)
Where rockhounds find zeophyllite
Classic worldwide localities
- Salmon River district, near Riggins, Idaho Co., Idaho, USA
- Schellkopf, near Brenk, Eifel district, Germany
- Monte Somma, Campania, Italy
- Khibiny massif, Kola Peninsula, Russia
- Göbnehall Yuglingarum, Skåne, Sweden
- Mont Saint-Hilaire, Quebec, Canada
Field-hunting tip
Where it forms: In cavities, as a secondary mineral from hydrothermal alteration of basalt (Litoměřice, Czech Republic). If you start seeing zeolites, apophyllite in float, you are in the right ground. Typical habit: platy, radial, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify zeophyllite?+
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What rocks look like zeophyllite?+
What minerals are found with zeophyllite?+
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Find zeophyllite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
