metamorphic
Green Gneiss or Greenschist
Chlorite/Actinolite Gneiss or Schist
Hardness: 6-7 (approximate based on quartz/feldspar content); Color: Pale to medium green with dark bands; Luster: Dull to pearly; Crystal structure: Foliated or gneissic banding; Specific Gravity: 2.6-3.0.
- Hardness
- 6-7 (approximate based on quartz/feldspar content)
- Color
- Pale to medium green with dark bands
- Luster
- Dull to pearly
Identified More metamorphic →
Explore Green Gneiss or Greenschist in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (approximate based on quartz/feldspar content); Color: Pale to medium green with dark bands; Luster: Dull to pearly; Crystal structure: Foliated or gneissic banding; Specific Gravity: 2.6-3.0.
Formation & geological history
Formed through high-grade regional metamorphism of igneous or sedimentary rocks. The green color often indicates the presence of chlorite, epidote, or actinolite minerals formed at medium pressure and temperature.
Uses & applications
Primarily used as decorative stone, crushed stone for construction, or as paving and landscaping materials. Distinctive specimens are collected by geology enthusiasts.
Geological facts
The banded appearance, known as gneissic foliation, occurs as minerals segregate under intense pressure. Green varieties are often associated with ancient volcanic arcs or seafloor metamorphism.
Field identification & locations
Identify by looking for distinct, parallel mineral bands and the characteristic greenish hue. Common in Precambrian shield areas and mountain belts like the Appalachians or Alps. Collectors should look for crisp banding and resistance to scratching.
More like this
