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, 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.
