an unusual zeolite, a hydrated barium silicate that types vitreous white monoclinic crystals.
A hydrous silicate of alumina and baryta, occurring usually in white cruciform crystals; cross-stone.
A mineral belonging to the zeolite team, generally occurring in cruciform twin crystals which differ in color from white to yellow, purple, or brown. It's a hydrous silicate of aluminum and barium. Sometimes called cross-stone and andreolite.
How would you define harmotome?