igneous
Granite
Granodiorite / Granite (Phaneritic Igneous Rock)
Hardness: 6-7 Mohs; Color: Salt and pepper/pinkish-grey; Luster: Vitreous to dull; Crystal structure: Phaneritic (visible crystals of quartz, feldspar, and mica); Specific gravity: 2.6-2.7
- Hardness
- 6-7 Mohs
- Color
- Salt and pepper/pinkish-grey
- Luster
- Vitreous to dull
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Salt and pepper/pinkish-grey; Luster: Vitreous to dull; Crystal structure: Phaneritic (visible crystals of quartz, feldspar, and mica); Specific gravity: 2.6-2.7
Formation & geological history
Formed from the slow cooling of silica-rich magma deep underground. This specimen appears to be an intrusive igneous rock typical of continental crust, often billions of years old.
Uses & applications
Extensively used in construction for countertops, flooring, monuments, and as aggregate for roads and building foundations.
Geological facts
Granite makes up the core of most mountain ranges and constitutes a large part of the Earth's continental crust. It is one of the hardest and most durable common substances on the planet.
Field identification & locations
Identify in the field by its speckled appearance and visible crystals that are interlocked. Commonly found in mountainous regions or as glacial erratic stones in fields. It cannot be scratched by a steel knife.
