igneous
Granodiorite
Phaneritic Granodiorite
Hardness: 6-7 Mohs; Color: Salt and pepper (white/grey with dark spots); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Cleavage: Perfect on feldspars; Specific gravity: 2.6-2.7.
- Hardness
- 6-7 Mohs
- Color
- Salt and pepper (white/grey with dark spots)
- 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 (white/grey with dark spots); Luster: Vitreous to dull; Crystal structure: Phaneritic (coarse-grained); Cleavage: Perfect on feldspars; Specific gravity: 2.6-2.7.
Formation & geological history
Formed through the slow cooling of silica-rich magma deep within the Earth's crust, typically in subduction zones above convergent plate boundaries. Most are associated with large batholiths of Mesozoic or Cenozoic age.
Uses & applications
Extensively used in construction as crushed stone for road base, and as dimension stone for buildings, monuments, and countertops.
Geological facts
The Rosetta Stone, the famous artifact that helped linguists decrypt Egyptian hieroglyphs, was carved into a block of granodiorite (initially thought to be basalt).
Field identification & locations
Field Identification: Look for a phaneritic texture with more plagioclase than orthoclase feldspar, often distinguished by 'salt and pepper' appearance. Common in the Sierra Nevada mountains of California.
