White crystal aggregtaes of the rare phosphate mineral sasaite on a contrasting matrix. From: Skipton Caves, Mount Widderin, Victoria, Australia. — Photo: David Hospital · CC BY-SA 4.0
Sasaite
Sasaite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al₆(PO₄)₅(OH)₃·36H₂O.
It crystallizes in the orthorhombic crystal system.
Key properties: specific gravity 1.75; optically biaxial.
IMA symbol Sas, IMA status: approved, named in 1977.
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); in veinlets in slate (Cheshunt.
It is found associated with Variscite, strengite, phosphosiderite, leucophosphite, apatite.
The name refers to the South African Speleological Association (SASA), whose members collected the first specimens.