Epidote is an abundant rock-forming mineral, but one of secondary origin. It occurs in marble and schistose rocks of metamorphic origin. It is also a product of hydrothermal alteration of various minerals (feldspars, micas, pyroxenes, amphiboles, garnets, and others) composing igneous rocks.
Epidote is a silicate mineral that is typically observed in domestically metamorphosed rocks of low-to-slight grade. In those rocks, epidote is often associated with amphiboles, feldspars, quartz, and chlorite. It occurs as replacements of mineral grains which have been altered by using metamorphism.
Colour: Yellowish-green, green, brownish-green, black
Lustre: Vitreous, Pearly
Byssolite A variety of Amphibole Supergroup.
The specimen in the photo is From: Alchuri, Shigar Valley, Skardu District, Baltistan, Northern Areas, Pakistan