Greenschist

Physical Properties

Hardness: 3.5-4.5 on Mohs scale; Color: Dull green to dark greyish-green; Luster: Dull to pearly; Crystal structure: Foliated or schistose texture; Specific gravity: 2.8-3.0.

Formation & Geological History

Formed through low-grade regional metamorphism of mafic igneous rocks (like basalt) at temperatures of 300 to 450 degrees Celsius and moderate pressure.

Uses & Applications

Used primarily as decorative stone, in landscaping, and sometimes as a minor source of architectural stone or roofing material in localized areas.

Geological Facts

The green color comes from minerals like chlorite and epidote that form during metamorphism. It represents a specific 'facies' that helps geologists determine the pressure and temperature history of a mountain range.

Field Identification & Locations

Identify by its characteristic green hue and fine-grained, slightly layered (foliated) texture. Commonly found in orogenic belts such as the Appalachian Mountains or the Alps.

Identified on: 5/11/2026

Mode: Standard