Description
Feldspars may not be the rarest mineral group, but they are certainly among the most capable of displaying spectacular crystallographic forms and habits! Here is a Greek sanidine specimen (the high-temperature, fully disordered alkali feldspar) showing a beautifully clear Carlsbad twin. Adding even more interest, a third, non-twinned crystal is enclosed within the twin pair, forming an overall superb and unusual cluster. The blackish circular dots visible on the surfaces—and also included within the sanidine—are biotite, a mineral abundant in the volcanic host rock. A great specimen for collectors who appreciate crystallography—or for anyone eager to explore this field with an excellent example in hand!
LOCATION
Greece, Almopia, Kakourou
SIZE
2.7 cm
WEIGHT
12 g