metamorphic
Green Quartzite
Meta-quartzite with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2 + SiO2)
Hardness: 7 (Mohs scale); Color: Pale mint green to sage green due to chromium; Luster: Vitreous to pearly; Crystal structure: Granular, foliated due to mica; Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7
- Hardness
- 7 (Mohs scale)
- Color
- Pale mint green to sage green due to chromium
- Luster
- Vitreous to pearly
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: Pale mint green to sage green due to chromium; Luster: Vitreous to pearly; Crystal structure: Granular, foliated due to mica; Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7
Formation & geological history
Formed through the regional metamorphism of quartz-rich sandstone. High heat and pressure causes recrystallization of quartz grains. The green tint occurs when chromium-rich mica (fuchsite) is present in the parent sediment.
Uses & applications
Used primarily as decorative dimension stone, aquarium gravel, garden landscaping, flagstone, and occasionally in lapidary work for cabochons or carvings.
Geological facts
Quartzite is so hard it will scratch glass and steel. This specific green variety is often sold under the trade name 'Aventurine' in the gemstone market if it exhibits shimmering 'aventurescence'.
Field identification & locations
Identify by its ability to scratch glass and its granular, sugary texture on broken surfaces. Commonly found in Brazil, India, and parts of the United States like Utah and Arizona.
More like this
