Stracherite
A calcium silicate-carbonate-phosphate of surprising structure, from Israel's Hatrurim Formation.
Intro adapted from Wikipedia (CC BY-SA).
Stracherite is an IMA-recognized mineral species in the silicate class, with the chemical formula BaCa₆(SiO₄)₂[(PO₄)(CO₃)]F.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Zadovite structural group.
Key properties: Mohs hardness 5; specific gravity 3.365; White streak; Vitreous luster; optically uniaxial.
IMA symbol Stra, IMA status: approved, named in 2017.
Found in pyrometamorphic spurrite marbles and formed under the influence of by-products (gases, fluids) of combustion metamorphism.
It is found associated with Spurrite, calcite, brownmillerite, shulamitite, CO3-bearing fluorapatite, fluormayenite- fluorkyuygenite, ariegilatite, periclase, brucite, barytocalcite.
The mineral was named to honor American geologist, Glenn Blair Stracher (aka “The Firewalker”) (b. 1949), Professor Emeritus of Geology, East Georgia State College, Swainsboro, Georgia, USA.