Epidote Tumbled

Epidote is a silicate mineral that is often found in metamorphic and igneous rocks, and is used as a pigment: 

Color: Epidote is typically yellowish green to pistachio green in color. 
Chemical formula: Epidote's chemical formula is Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH). 
Uses: Epidote is used as a pigment in tempera, watercolor, gouache, oil, acrylics, cement, and fresco. 
Formation: Epidote is formed during low to medium grade metamorphism, and hydrothermal activity. It can also be a product of the alteration of other minerals, such as plagioclase, pyroxene, and amphiboles. 
Locations: Epidote can be found in many places around the world, including eastern France, Russia, Austria, Italy, and the United States. 
Appearance: Epidote can occur as hard, lustrous crystals, or as vug or vein fillings in rocks. 
Associated minerals: Epidote is often associated with chlorite, actinolite, and quartz. 
Other names: When epidote is especially abundant, it forms a monomineralic rock called “epidosite”.