top of page
Gneiss
schist, porphyritic, amphibolite, quartzite
Other Names:
schist, porphyritic, amphibolite, quartzite
Pronunciation:
nise
Type:
Metamorphic
Classification:
High-grade Metamorphic rock
Chemical Formula/Composition:
Feldspars, Quartz, Mica, Amphibole
Luster:
Dull
Color:
Black, Brown, Pink, Red, White
Transparency:
Opaque
Mohs Hardness:
6 - 7
Fracture/Cleavage:
Irregular
Uses:
Building Stone, Decorative, Aggregate, Landscaping
Key Features:
In traditional English and North American usage, gneiss is a coarse-grained metamorphic rock showing compositional banding (gneissic banding) but poorly developed schistosity (mineral banding) and indistinct cleavage.
Sources:
bottom of page