igneous
Granodiorite (Weathered)
Granodiorite
Hardness: 6-7 on Mohs scale. Color: Light grey to white with dark flecks. Luster: Dull to sub-vitreous. Crystal Structure: Phaneritic (medium-grained). Specific Gravity: 2.6-2.7.
- Hardness
- 6-7 on Mohs scale
- Color
- Light grey to white with dark flecks
- Luster
- Dull to sub-vitreous
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale. Color: Light grey to white with dark flecks. Luster: Dull to sub-vitreous. Crystal Structure: Phaneritic (medium-grained). Specific Gravity: 2.6-2.7.
Formation & geological history
Formed through the slow cooling of silica-rich magma beneath the Earth's surface in batholiths and mountain-building regions. This specimen shows significant rounding and weathering from water or glacial transport.
Uses & applications
Used primarily as crushed stone for road construction, concrete aggregate, and occasionally as architectural dimension stone similar to granite.
Geological facts
Granodiorite is the main rock type in the Sierra Nevada mountains and is the same rock type as the famous Rosetta Stone. It is intermediate between granite and diorite.
Field identification & locations
Identify in the field by its 'salt and pepper' appearance (plagioclase/quartz mixed with dark minerals like biotite or hornblende). Often found in riverbeds or glacial tills far from its source rock.
