This pieces was pictured in several “Wilensky Mineral Video” advertisements that appeared in “The Mineralogical Record” and “Rocks and Minerals” magazine during the early to mid 1990’s.
I would sell this piece for US$10,000. It is a superb combinatioin piece which includes a doubly terminated crystal of green apophyllite on a doubly terminated crystal of stilbite. This piece is from Jalgaon, North Maharastra (state), India and was found during the early 1990’s.
Both stilbite and apophyllite are silicate mineral species. Stilbite is also a zeolite mineral species. Zeolites are all hydrated aluminium silicates and they mostly occur in basalt vescicles and are deposited from aqueous solutions. Low temperature hydrothermal systems that deposit zeolites include water that is at about four hundred degrees centigrade. The apophyllite crystal on this piece is green because of a trace of vanadium that “contaminates” the apophyllite crystal lattice.