Faujasite-Ca is a rare member of the zeolite group often occurring as sharp, well-defined octahedral crystals in volcanic cavities. It is best known for its complex framework structure and is primarily prized by advanced mineral collectors. While it can occur in a few classic European and Canadian localities, it remains a challenging find for field collectors.
Is this faujasite-ca?
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 faujasite-ca with a known reference. Faujasite-Ca 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.
- 4Match the color rangeCompare against the expected color range: colorless, white, pale brown.
- 5Look at form & habitCrystal system: cubic. Typical habit: crystalline.
Often confused with
Faujasite-Ca vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside faujasite-ca
Minerals reported to co-occur with faujasite-ca. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ca,Na₂,Mg)₃₅Al₇₀Si₁₂₂O₃₈₄·235H₂O
- Mohs hardness
- 5
- Density
- 1.923-1.94 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Crystalline
- Cleavage
- Perfect on {111}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Usually occurs in basaltic volcanics, metapyroxenite, also with augite in limburgite
Where rockhounds find faujasite-ca
Classic worldwide localities
- Found in drill core from Haselborn, near Ilbeshausen, Vogelsberg, Hessen, Germany (type locality)
Field-hunting tip
Where it forms: Usually occurs in basaltic volcanics, metapyroxenite, also with augite in limburgite. If you start seeing augite, nepheline, calcite in float, you are in the right ground. Typical habit: crystalline. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify faujasite-ca?+
Where is faujasite-ca found?+
What rocks look like faujasite-ca?+
What minerals are found with faujasite-ca?+
What kind of rock does faujasite-ca form in?+
What is faujasite-ca used for?+
Find faujasite-ca on the map
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