Chabazite-Ca is a common zeolite mineral recognized by its characteristic rhombohedral crystals that often mimic cubes. It is most frequently collected from amygdaloidal cavities in basaltic rocks where it forms alongside other zeolite species. Collectors look for its glassy luster and distinctive crystal twinning patterns.
Is this chabazite-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 chabazite-ca with a known reference. Chabazite-Ca sits at Mohs 4-5, 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: white, colorless, green, yellow, pink.
- 5Look at form & habitCrystal system: triclinic. Typical habit: druse, pseudo cubic.
Often confused with
Chabazite-Ca vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside chabazite-ca
Minerals reported to co-occur with chabazite-ca. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Al₄Si₈O₂₄·13H₂O
- Mohs hardness
- 4-5
- Density
- 2.05-2.20 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Druse, pseudo cubic
- Cleavage
- {10*1}, distinct
- Rarity
- Common
- Uses
- Collector, Geological study
- Host rock
- In volcanic rocks as basalts, andesite; rarer in limestones and schists; hydrothermally deposited in cavities and joints in ore veins
Where rockhounds find chabazite-ca
Classic worldwide localities
- Paterson, Passaic Co., and Bergen Hill, Hudson Co., New Jersey, USA
- Table Mountain, Jefferson Co., Colorado, USA
- Goble, Columbia Co., and Springfield, Lane Co., Oregon, USA
- Idar-Oberstein, Rhineland-Palatinate, Germany
- Kilmalcolm, Renfrewshire, Scotland
- Haeddin, on Eysturoy
Field-hunting tip
Where it forms: In volcanic rocks as basalts, andesite; rarer in limestones and schists; hydrothermally deposited in cavities and joints in ore veins. If you start seeing zeolites, nepheline, melilite in float, you are in the right ground. Typical habit: druse, pseudo cubic. Train your eye for that shape before scanning the outcrop.







