Tags: Chemical Substance, Mineral.
Avogadrite ((KCs)BF4) is a potassium-caesium tetrafluoroborate. Avogadrite crystallizes in the orthorhombic system (space group Pnma) with cell parameters a 8.66 Å b 5.48 Å and c Å 7.03. The mineral is only found as a sublimation product around volcanic fumaroles.