Minyulite Locality: Tom's Phosphate quarry (Tom's quarry), Kapunda, North Mt Lofty Ranges, Mt Lofty Ranges, South Australia, Australia Colourless Minyulite xls. Field of view 4 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Minyulite
A rare potassium-aluminium phosphate-fluoride forming radiating fibrous sprays in phosphatic ironstone cracks.
Intro adapted from Wikipedia (CC BY-SA).
Minyulite is an IMA-recognized mineral species in the phosphate class, with the chemical formula KAl₂(PO₄)₂F·4H₂O.
It crystallizes in the orthorhombic crystal system (space group Pba2).
Key properties: Mohs hardness 3.5; specific gravity 2.45; Vitreous, silky in aggregates luster; refractive index 1.534; optically biaxial.
IMA symbol Myu, grandfathered status — known before the IMA’s founding, named in 1933.
Found in weathered glauconitic phosphatic ironstone (Australia).
It is found associated with Dufrénite, apatite, fluellite, wavellite, variscite, leucophosphite.
The name refers to Minyulo Well, Western Australia, near the source of the first specimens.