HISTORY, NAME, OCCURRENCE: Mineralogists recognized epidote as a distinct species in 1801. The origin of its name is uncertain, but may stem from the Greek epidosis, meaning “increase,” alluding to one side of the crystal being longer than the other. Epidote is widespread and common, but few sources yield collectible specimens. Notable localities include Peru, Mexico, Austria, France, Afghanistan, Namibia, Russia, Pakistan, Australia, and the United States (Colorado, Alaska, New Mexico, California).
MINERALOGY, PROPERTIES, OCCURRENCE: Epidote [basic calcium aluminum iron silicate, Ca2Al2(Fe,Al)Si3O12(OH)], pronounced EH-peh-dote, crystallizes in the monoclinic system as thick, tabular crystals or long, slender prisms that are typically well-developed, deeply striated, and terminated by two slanting faces. It has a Mohs hardness of 6.0-7.0, perfect cleavage in one direction, a specific gravity of 3.3-3.6, and a color that ranges from yellowish-green and pistachio-green to greenish-black. Epidote is a sorosilicate or double-tetrahedral silicate that occurs in several mineralogical environments including granite pegmatites, basaltic cavities, and contact and regional metamorphic rocks.
METAPHYSICAL PROPERTIES, LORE, USES: Powdered epidote was prescribed by medieval physicians as a tonic to improve overall physical well-being. Modern metaphysical practitioners consider epidote to be a stone of empowerment and fulfillment that aids personal transformation and evolution. Epidote has no technological uses.
COLLECTORS’ INFORMATION: Epidote is collected as both individual and composite specimens for its high degree of crystal development and range of green colors.