EPIDOTE

Ca2(Al, Fe)3(SiO4)3(OH)
Calcium Aluminum Iron Silicate Hydroxide

 Cleavage: good in one direction lengthwise

 Colour: pistachio green to yellowish or brownish green, also brown to black

 Fracture: uneven to conchoidal

 Hardness: 6-7

 Luster: vitreous

 Streak: white to gray

 Possible Useage: mineral specimen, rarely as a gemstone

 More Info: Mineral Gallery, Mineralogy Database