Fransoletite is a rare phosphate mineral typically found as white, bladed crystals or radial aggregates in phosphate-rich pegmatites. It is highly sought after by advanced micromount collectors due to its rarity and specific formation conditions in altered beryllonite zones.
Is this fransoletite?
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 fransoletite with a known reference. Fransoletite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Fransoletite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Fransoletite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: bladed crystals, radial aggregates, crusts.
Often confused with
Fransoletite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside fransoletite
Minerals reported to co-occur with fransoletite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃Be₃(PO₄)₂(OH)₂·4H₂O
- Mohs hardness
- 3
- Density
- 2.47 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Bladed Crystals, Radial Aggregates, Crusts
- Cleavage
- Perfect On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-500 depending on specimen size and matrix quality
Where rockhounds find fransoletite
Classic worldwide localities
- Tip Top mine, South Dakota, USA
- Hagendorf, Bavaria, Germany
Field-hunting tip
Look in granite pegmatites country — that is the host setting where fransoletite typically forms. If you start seeing beryllonite, herderite, roscherite in float, you are in the right ground. Field specimens usually show a bladed crystals, radial aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fransoletite?+
Where is fransoletite found?+
How much is fransoletite worth?+
What rocks look like fransoletite?+
What minerals are found with fransoletite?+
What kind of rock does fransoletite form in?+
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Find fransoletite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
