Clear euclase crystal (about 0.5 mm long) from the Chandler Mine in Raymond, New Hampshire. Harvard Mineral Museum specimen, #121054. (Photo courtesy Peter Cristofono; unauthorized reproduction is prohibited.)

Formula: BeAlSiO4(OH) Monoclinic


Euclase is a rare mineral found in complex granite pegmatites.

MARATHON COUNTY: Euclase is reported in the granite pegmatites cutting the Wausau complex (Falster, correspondence 1986, WGNHS files).