Barrerite is a relatively rare member of the zeolite group that forms as a late-stage mineral in volcanic cavities. It is visually similar to stilbite, often requiring chemical or structural testing for positive identification. It is most sought after by advanced collectors for its distinct, though rare, aesthetic crystal forms.
Is this barrerite?
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 barrerite with a known reference. Barrerite sits at Mohs 3-4, 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, pink.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular crystals, often elongated or radiating aggregates.
Often confused with
Barrerite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside barrerite
Minerals reported to co-occur with barrerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Al₂Si₇O₁₈·6H₂O
- Mohs hardness
- 3-4
- Density
- 2.13 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular crystals, often elongated or radiating aggregates
- Cleavage
- Perfect on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- On the walls of large fractures in deeply weathered andesitic and rhyolitic lavas
Where rockhounds find barrerite
Classic worldwide localities
- Found near Capo Pula, below South Efisio Tower, Nora, Sardinia, Italy
Field-hunting tip
Where it forms: On the walls of large fractures in deeply weathered andesitic and rhyolitic lavas. If you start seeing heulandite in float, you are in the right ground. Typical habit: tabular crystals, often elongated or radiating aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify barrerite?+
Where is barrerite found?+
What rocks look like barrerite?+
What minerals are found with barrerite?+
What kind of rock does barrerite form in?+
What is barrerite used for?+
Find barrerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
