Garronite-Na is a rare member of the zeolite group typically found as small, radiating clusters of prismatic crystals in vugs within basaltic rocks. It is most easily identified by its characteristic pseudotetragonal habit and association with other zeolites in volcanic settings, though it often requires XRD analysis for definitive verification due to its similarity to gismondine.
Is this garronite-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 garronite-na with a known reference. Garronite-Na sits at Mohs ~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; frosted aggregates.
- 4Match the color rangeCompare against the expected color range: pale yellow, white aggregates.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: pseudotetragonal prismatic crystals, radiating clusters, crusts.
Often confused with
Garronite-Na vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside garronite-na
Minerals reported to co-occur with garronite-na. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₆(Al₆Si₁₀O₃₂)·8.5H₂O
- Mohs hardness
- ~4
- Density
- 2.19 g/cm³
- Colors
- Pale yellowWhite aggregates
- Streak
- White
- Luster
- Vitreous; frosted aggregates
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Pseudotetragonal prismatic crystals, radiating clusters, crusts
- Cleavage
- Good parting on {011}
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In vugs in a hydrothermally-altered zone of the Poudrette pegmatite and in sodalite-rich segregations in nepheline syenite both part of an alkaline igneous intrusive complex
Where rockhounds find garronite-na
Classic worldwide localities
- Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Quebéc, Canada
Field-hunting tip
Where it forms: In vugs in a hydrothermally-altered zone of the Poudrette pegmatite and in sodalite-rich segregations in nepheline syenite both part of an alkaline igneous intrusive complex. If you start seeing phillipsite, chabazite, thomsonite in float, you are in the right ground. Typical habit: pseudotetragonal prismatic crystals, radiating clusters, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify garronite-na?+
Where is garronite-na found?+
What rocks look like garronite-na?+
What minerals are found with garronite-na?+
What kind of rock does garronite-na form in?+
What is garronite-na used for?+
Find garronite-na on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
