Pliniusite
Pliniusite is an IMA-recognized mineral species in the vanadate class, with the chemical formula Ca₅(VO₄)₃F.
It crystallizes in the hexagonal crystal system (space group P6_3/m). It is a member of the Apatite structural group.
Key properties: Mohs hardness 5; specific gravity 3.402; White streak; Vitreous luster; optically uniaxial.
IMA symbol Pli, IMA status: approved, named in 2018.
Forms as a sublimate at an active volcanic fumarole and a paleo-fumarole (Russia) and in pyrometamorphic paralava (Israel). A combination of high temperature, low pressure.
It is found associated with Hematite, tenorite, diopside, andradite, kainotropite, baryte, volborthite, brochantite, gypsum, opal (Mountain 1004, Tolbachik); anhydrite, diopside.
The mineral was named to honor the Roman naturalist, natural philosopher, author, and statesman Pliny the Elder, born Gaius Plinius Secundus (AD 23-79).