Apophyllite crystallizes as pseudo-cubic crystals, granular masses, natural pyramidal structures, and as druse upon other minerals. It can occur in green, white, grayish, yellowish, rose-red tint, and clear/colorless forms. Apophyllite was first reported in 1806 by R.J. Haüy. It was named for the Greek words meaning “get” and “leaf,” due to its tendency to exfoliate when heated under a blowpipe.
Chemical composition: KFCₐ(SiO₅)₄ 8H₂O ; Hardness 4.5 – 5
Stilbite is a subgroup of the Zeolite Group (a large number of aluminosilicates). Stilbite-Ca occurs commonly in fracture and cavities of basaltic rock. The crystal structure of Stilbite consists of two sets of connected channels. Color is usually white but can vary. Chemical composition in this series can range; Hardness: 3.5-4.
