Vantasselite, from Bihain, Vielsalm, Luxembourg Province, Belgium — Photo: David Hospital - www.purple-sky-minerals.com · CC BY-SA 3.0
Vantasselite
A white pearly hydrated aluminium phosphate of orthorhombic habit.
Intro adapted from Wikipedia (CC BY-SA).
Vantasselite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al₄(PO₄)₃(OH)₃·9H₂O.
It crystallizes in the orthorhombic crystal system (space group Pmam).
Key properties: Mohs hardness 2–2.5; specific gravity 2.3; Pearly on cleavages luster; optically biaxial.
IMA symbol Vts, IMA status: approved, named in 1986.
On dumps in a quartzite quarry, in quartz veinlets or lining schistosity planes.
It is found associated with Wavellite, cacoxenite, variscite, turquoise, lithiophorite, cryptomelane, quartz, clinochlore, muscovite.
The mineral was named to honor Dr. René Van Tassel (1916–), mineralogist, Royal Institute of Natural Sciences, Brussels, Belgium, for his work on Belgian mineralogy.