Tenebrescent scapolite from Afghanistan
Shane F. McClure1, George R. Rossman2,
James E. Shigley1
1GIA
Research Laboratory
Carlsbad, CA 92008, USA
2Division of Geological &
Planetary Sciences
California Institute of Technology, Pasadena, CA 91125-2500, USA
Abstract
Marialite, a member of the scapolite group, was obtained from
Badakhshan, Afghanistan. Unlike most hackmanite which changes from
light yellow to pink when exposed to sunlight and UV light,
respectively, the Afghanistan scapoilte turns from colorless to deep blue
upon exposeure to short-wave UV radiation. It's chemical analysis showed that it contained sulfide: Na4Al3Si9O24Cl0.9S0.09, the ion that is responsible for photochemical color changes in hackmanite and tugtupite.
last updated, Feb 28, 2018