Stronalsite is an extremely rare strontium-dominant feldspar-group mineral found in alkaline rock complexes. It typically appears as small, white to colorless grains or crystals that are structurally related to banalsite, often requiring laboratory verification to distinguish from other feldspars.
Is this stronalsite?
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 stronalsite with a known reference. Stronalsite sits at Mohs 6.5, 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.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: equant to prismatic crystals, granular aggregates.
Often confused with
Stronalsite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside stronalsite
Minerals reported to co-occur with stronalsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SrNa₂(Al₄Si₄O₁₆)
- Mohs hardness
- 6.5
- Density
- 2.95 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Equant to prismatic crystals, granular aggregates
- Cleavage
- Rectangular parting suspected
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary alteration mineral in veins cutting mafic metatu® xenoliths (Rendai, Japan); in veinlets and grains in jadeitic aggregates within serpentinite (Mt. Ohsa, Japan)
Where rockhounds find stronalsite
Classic worldwide localities
- Rendai, Kochi City, Japan (type locality)
Field-hunting tip
Where it forms: A secondary alteration mineral in veins cutting mafic metatu® xenoliths (Rendai, Japan); in veinlets and grains in jadeitic aggregates within serpentinite (Mt. Ohsa, Japan). If you start seeing pectolite, slawsonite, albite in float, you are in the right ground. Typical habit: equant to prismatic crystals, granular aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify stronalsite?+
Where is stronalsite found?+
What rocks look like stronalsite?+
What minerals are found with stronalsite?+
What kind of rock does stronalsite form in?+
What is stronalsite used for?+
Find stronalsite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
