Very rare Pb-Cu-selenium mineral approved in 2007 (IMA 2007-012) that occurs as aggregates of sky blue acicular crystals in a contrasting matrix. Analyzed specimen by Raman. From: La Gasquie, Cuzac, Lot, Occitanie, France. — Photo: David Hospital · CC BY-SA 4.0
Munakataite
Munakataite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Pb₂Cu₂(Se⁴⁺O₃)(SO₄)(OH)₄.
It crystallizes in the monoclinic crystal system (space group P2_1/m). It is a member of the Linarite structural group.
Key properties: Mohs hardness 2; specific gravity 5.526; Bluish white streak; Vitreous, pearly on cleavage surfaces. Easily mistaken visually for linarite luster.
IMA symbol Mkat, IMA status: approved, named in 2007.
Found as a secondary mineral in the weathering zone of a polymetallic sulfide deposit.
It is found associated with Malachite.
The name refers to the city of Munakata, where the Kato mine, source of the first specimens, is located.