Prehnite is a translucent to transparent hydrated calcium aluminum silicate in the orthorhombic crystal class, usually found in radiating botryoidal (grape-like) aggregate forms, and rarely as tabular and pyramidal crystals. Prehnite is sometimes confused with apatite, jade or serpentine.
Epidote is a calcium aluminum iron silicate mineral that is found in low-to-moderate grade metamorphosed rocks. It is often associated with Amphiboles, Feldspars, Quartz, and Chlorite. It occurs as replacements of mineral grains that have been altered by metamorphism. Epidote is also found in Unakite.