igneous
Granite Cobble
Phaneritic Felsic Igneous Rock
Hardness: 6-7 on Mohs scale. Color: Mottled grey, tan, and orange-yellow. Luster: Vitreous to dull. Crystal structure: Phaneritic (visible crystals). Specific gravity: 2.63-2.75.
- Hardness
- 6-7 on Mohs scale
- Color
- Mottled grey, tan, and orange-yellow
- 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 on Mohs scale. Color: Mottled grey, tan, and orange-yellow. Luster: Vitreous to dull. Crystal structure: Phaneritic (visible crystals). Specific gravity: 2.63-2.75.
Formation & geological history
Formed from the slow cooling of silica-rich magma deep underground (plutonic). This specimen appears water-worn, suggesting transport via river or glacial activity.
Uses & applications
Commonly used in construction, road base, and landscaping. High-quality slabs are used for countertops and monuments.
Geological facts
Granite makes up a large portion of the Earth's continental crust. The yellow-orange tint in this specimen likely comes from iron oxide staining or secondary weathering of feldspars.
Field identification & locations
Identify in the field by its interlocking crystalline texture and lack of layering. Found globally in mountainous regions and glacial till.
