metamorphic
Gneiss
Gneiss
Hardness: 6-7 (Mohs); Color: Banded pink (feldspar), white (quartz), and black/grey (biotite/hornblende); Luster: Vitreous to dull; Structure: Foliated (gneissic banding); Specific Gravity: 2.6-2.9
- Hardness
- 6-7 (Mohs)
- Luster
- Vitreous to dull
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs); Color: Banded pink (feldspar), white (quartz), and black/grey (biotite/hornblende); Luster: Vitreous to dull; Structure: Foliated (gneissic banding); Specific Gravity: 2.6-2.9
Formation & geological history
Formed through high-grade regional metamorphism of igneous (granite) or sedimentary protoliths. This specimen likely originates from the metamorphic complexes of the Eastern Alps or the Bohemian Massif in Central Europe.
Uses & applications
Used as a dimension stone for flooring, facades, and gravestones. Crushed stone is used in road construction and as railway ballast. High aesthetic value for landscaping.
Geological facts
Gneiss is one of the oldest known rock types on Earth, with some specimens dated at over 4 billion years old. The term comes from the German 'Gneis', meaning 'sparked' or 'glittering'.
Field identification & locations
Identified by the distinct alternating layers or bands of light and dark minerals. Common in mountainous regions like the Alps near Eisenstadt (approx. 47.7N). Look for 'salty' and 'peppery' granular texture with parallel alignment.
More like this
