Epidote Water-Worn Pebble

Physical Properties

Hardness: 6-7 Mohs; Color: Pistachio green to dark forest green with possible gray or tan patches; Luster: Vitreous to dull (weathered); Crystal structure: Monoclinic; Cleavage: Perfect in one direction; Specific gravity: 3.3-3.6

Formation & Geological History

Formed through low-to-medium grade regional or contact metamorphism of calcium-rich rocks like basalt or limestone. This specific specimen has been smoothed by water action in a river or coastal environment.

Uses & Applications

Low-grade gemstones, ornamental stones, and significant geological indicators for metamorphic facies. Often collected by hobbyists for tumbling.

Geological Facts

Epidote's hallmark is its unique 'pistachio' green color. It is often found in association with quartz, feldspar, and chlorite. Its name is derived from the Greek word 'epidosis' meaning 'addition'.

Field Identification & Locations

Identify by its distinctive shade of green and its hardness (it will scratch glass). Commonly found in riverbeds, glacial tills, and near metamorphic outcrops in mountainous regions.

Identified on: 4/28/2026

Mode: Standard