Watatsumiite
Watatsumiite is an IMA-recognized mineral species in the silicate class, with the chemical formula LiNa₂KMn₂V₂Si₈O₂₄.
It crystallizes in the monoclinic crystal system (space group Cc). It is a member of the Neptunite structural group.
Key properties: Mohs hardness 5.5–6; specific gravity 3.24; White with a greenish tint streak; Vitreous luster; optically biaxial.
IMA symbol Wts, IMA status: approved, named in 2001.
Found in veinlets in a metamorphosed Mn deposit.
It is found associated with “Potassicleakeite”, quartz, K-feldspar, serandite, suzukite, roscelite, copper, chalcopyrite, yarrowite.
The name refers to Watatsumi, the Japanese god of the sea, in recognition that the mineral is the V and Mn analog of neptunite, whose name alludes to Neptune, the Roman god of the sea.