armenite

noun

1. An orthorhombic-pyramidal mineral containing aluminum, barium, calcium, hydrogen, oxygen, and silicon.

   “Pure armenite is colorless and has well developed prismatic pseudohexagonal crystals with poorly developed terminal faces.”

   “All reported armenites are of nearly end-member composition.”

   “Although armenite contains 10 inequivalent Si-positions, only the topochemically distinct Si sites are resolved in the NMR spectrum.”