Sasaite is a very rare aluminum phosphate mineral found as delicate, pearly white radial aggregates or platy crystals. It typically occurs as a secondary mineral in hydrothermal lead-zinc deposits, often forming within cavities of altered ore.
Is this sasaite?
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 sasaite with a known reference. Sasaite sits at Mohs 2-3, 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: pearly.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: earthy, nodular.
Often confused with
Sasaite vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Variscite is the harder of the two (Mohs 4.5 vs. 2-3); luster reads pearly on Sasaite and vitreous to waxy on Variscite.

How to tell apart: Luster reads pearly on Sasaite and vitreous to resinous, pearly on Wavellite.
Often found alongside sasaite
Minerals reported to co-occur with sasaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₆(PO₄)₅(OH)₃·36H₂O
- Mohs hardness
- 2-3
- Density
- 1.75 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Earthy, nodular
- Cleavage
- On {001}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Rarely formed from acidic phosphate-sulfate-rich solutions derived from bat guano reacting with clay minerals in cave soil (West Driefontein Cave, South Africa; Skipton lava tube caves, Australia)
Where rockhounds find sasaite
Classic worldwide localities
- West Driefontein Cave, Carlstonville, west Transvaal, South Africa
- Skipton lava tube caves, 40 km southwest of Ballarat, and near Cheshunt, Victoria, Australia
- Rapid Creek, Yukon Territory, Canada
- Feengrotten (Cave), near Saalfeld, Thuringia, Germany
Field-hunting tip
Where it forms: Rarely formed from acidic phosphate-sulfate-rich solutions derived from bat guano reacting with clay minerals in cave soil (West Driefontein Cave, South Africa; Skipton lava tube caves, Australia). If you start seeing variscite, strengite, phosphosiderite in float, you are in the right ground. Typical habit: earthy, nodular. Train your eye for that shape before scanning the outcrop.




