Quartz, calcite - Piedras Verdes, Mexico, 193 grams
Interesting piece composed of quartz crystals covered by calcite scalenohedra, the back of the sample being partially reddened by a ferric coating.It comes from Piedras verdes, Urique, Chihuahua in Mexico.This piece measures 10.2 cm long by 6.7 cm wide and 4.1 cm at the thickest.Its weight is 193...