A small fragment of the very rare mineral misenite from the type locality in Miseno (Cap Miseno, Naples Province, Campania, Italy), where it is extremely rare. Misenite has only been found in two localities worldwide. — Photo: David Hospital · CC BY-SA 4.0
Misenite
Misenite is an IMA-recognized mineral species in the sulfate class, with the chemical formula K₈(SO₄)(SO₃OH)₆.
Key properties: specific gravity 2.32; Pearly to silky luster; optically biaxial.
IMA symbol Mse, grandfathered status — known before the IMA’s founding, named in 1849.
Very rarely formed under fumarolic conditions.
It is found associated with Potassium alum, alunogen, halotrichite, metavoltine, pickeringite, sulfur, tamarugite, voltaite (Cape Miseno, Italy).
The name refers to its occurrence on Cape Miseno, Italy.