Cochise College          Photos of Minerals

                          Geology Home Page                

                          Roger Weller, geology instructor

                          wellerr@cochise.edu
                                  copyright 2007-R.Weller

 

Mineral Information on:
epidote


Chemical Group:    silicate

Chemical Formula:   
HCa2(Al,Fe)3Si3O13

Color:  pistachio-green, pea soup green, brownish green, greenish black, black, red, 
     gray, grayish white

Transparency:  transparent to opaque

 

Hardness: 6 to 7         Specific Gravity:  3.25 to 3.5             Fracture:

Cleavage: one direction

 

Crystal Forms and Habits:  Monoclinic system
     Crystals are prismatic.
     Epidote commonly forms as a thin coating along fractures in rocks.
     Epidote also is commonly found in massive form.

Mineral Associations: a common metamorphic mineral

Identifying Characteristics:  its distinct yellow-green color and massive nature

Uses:  when combined with pinkish orange feldspar, as a gemstone (unakite)

USA occurrences:
Alaska
     Prince of Wales island
Arizona
     Wickenburg, Jerome. Bagdad, Castle Hot Springs, Cave Creek
California
     Inyo, Mono, El Dorado, Fresno, Kern, and San Diego Counties
Colorado
     Idaho Springs
Michigan
     Lake Superior region
Montana
     Missouri River
New Mexico
     Taos, Orogrande, Silver City, Santa Fe
North Carolina
     Spruce Pine, Bakersville, Burnsville, Dyartsville
Pennsylvania
     Pine Mountain
     Adams County
Tennessee
     Roan Mountain
     Townsend
Texas
     Enchanted Rock,Texas Hill Country
Virginia
     Royal Front (unakite)
     Page County
     Rose River
     Greene, Nelson, Albemarle, and Rockbridge counties
WORLD-WIDE occurrences:

Toxicity:      when-swallowed- low         when inhaled- moderate

Additional Information: 
     A stone containing green epidote and salmon-colored feldspar is
a gemstone known as unakite.
     An alternative name for epidote is pistacite (in reference to the color
of the pistachio nut).