Stilbite-Na is most recognizable for its distinctive bowtie-shaped or sheaf-like crystal aggregates. It is a common zeolite found primarily in the cavities of basaltic volcanic rocks, often occurring in beautiful, aesthetic clusters alongside other zeolites like heulandite and apophyllite.
Is this stilbite-na?
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 stilbite-na with a known reference. Stilbite-Na sits at Mohs 3.5-4, 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 to pearly.
- 4Match the color rangeCompare against the expected color range: white, red, yellow, brown, cream.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fibrous, globular, wheat sheaf.
Often confused with
Stilbite-Na vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside stilbite-na
Minerals reported to co-occur with stilbite-na. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₉(Si₂₇Al₉)O₇₂·28H₂O
- Mohs hardness
- 3.5-4
- Density
- 2.1-2.2 g/cm³
- Streak
- White
- Luster
- Vitreous to pearly
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Fibrous, globular, wheat sheaf
- Cleavage
- Perfect on {010}
- Rarity
- Common
- Uses
- Collector, Specimen
- Host rock
- Amygdaloidal cavities in basalts and similar rocks
Where rockhounds find stilbite-na
Classic worldwide localities
- Capo Pula, Cagliari, Sardinia, Italy (type locality)
Field-hunting tip
Where it forms: Amygdaloidal cavities in basalts and similar rocks. If you start seeing heulandite, apophyllite, quartz in float, you are in the right ground. Typical habit: fibrous, globular, wheat sheaf. Train your eye for that shape before scanning the outcrop.
More stilbite-na photos
Common questions
How do you identify stilbite-na?+
Where is stilbite-na found?+
What rocks look like stilbite-na?+
What minerals are found with stilbite-na?+
What kind of rock does stilbite-na form in?+
What is stilbite-na used for?+
Find stilbite-na on the map
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