Epidote in Quartz (Epidosite)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: pistachio-green to dark olive green; Luster: vitreous to resinous; Crystal structure: Monoclinic; Cleavage: perfect in one direction; Specific gravity: 3.3-3.6

Formation & Geological History

Formed through regional or contact metamorphism of calcium-rich rocks or the hydrothermal alteration of igneous rocks usually in low-to-medium grade metamorphic facies.

Uses & Applications

Primarily used as a collector specimen, semi-precious gemstone in jewelry (when high quality), and occasionally as a decorative stone in landscaping.

Geological Facts

The name Epidote comes from the Greek word 'epidosis' which means 'addition', referring to the crystal's geometry. It is a common constituent of greenstone and is frequently found with quartz and feldspar.

Field Identification & Locations

Identify in the field by its distinct 'pistachio' green color and relatively high hardness. It is common in alpine veins and areas with hydrothermally altered basalt.

Identified on: 5/3/2026

Mode: Standard