Parafransoletite is a rare beryllium phosphate mineral that typically forms as delicate, acicular to fibrous white crystals. It is most commonly found as a secondary mineral in complex granite pegmatites, often associated with other rare phosphate species. Because of its rarity and fragile nature, it is highly sought after by advanced micromount collectors.
Is this parafransoletite?
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 parafransoletite with a known reference. Parafransoletite sits at Mohs ~2.5, 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, silky in aggregates.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: triclinic. Typical habit: radial, spear head, wheat sheaf.
Often confused with
Parafransoletite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside parafransoletite
Minerals reported to co-occur with parafransoletite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃Be₂(PO₄)₂(PO₃OH)₂·4H₂O
- Mohs hardness
- ~2.5
- Density
- 2.54 g/cm³
- Streak
- White
- Luster
- Vitreous, silky in aggregates
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Radial, spear head, wheat sheaf
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary hydrothermal mineral on fracture surfaces in beryl in a complex granite pegmatite
Where rockhounds find parafransoletite
Classic worldwide localities
- Tip Top mine, 8.5 km southwest of Custer, Custer Co., South Dakota, USA
Field-hunting tip
Where it forms: A rare secondary hydrothermal mineral on fracture surfaces in beryl in a complex granite pegmatite. If you start seeing beryl, mitridatite, whitlockite in float, you are in the right ground. Typical habit: radial, spear head, wheat sheaf. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify parafransoletite?+
Where is parafransoletite found?+
Is parafransoletite safe to handle?+
What rocks look like parafransoletite?+
What minerals are found with parafransoletite?+
What kind of rock does parafransoletite form in?+
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Find parafransoletite on the map
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