igneous
Granite Cobble
Phaneritic Felsic Igneous Rock
Hardness: 6-7 Mohs; Color: Pinkish-tan with black and clear specs; Luster: Dull (weathered) to vitreous (on fresh surfaces); Crystal Structure: Phaneritic (visible grains of quartz, feldspar, and mica); Specific Gravity: 2.63-2.75
- Hardness
- 6-7 Mohs
- Color
- Pinkish-tan with black and clear specs
- Luster
- Dull (weathered) to vitreous (on fresh surfaces)
Identified More igneous →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 Mohs; Color: Pinkish-tan with black and clear specs; Luster: Dull (weathered) to vitreous (on fresh surfaces); Crystal Structure: Phaneritic (visible grains of quartz, feldspar, and mica); Specific Gravity: 2.63-2.75
Formation & geological history
Formed through the slow crystallization of magma below Earth's surface. This specific specimen is a water-worn river stone or glacial cobble, rounded by mechanical erosion over thousands of years.
Uses & applications
Used in construction, countertops, monuments, and as decorative landscaping aggregate.
Geological facts
Granite makes up a large portion of the Earth's continental crust. The pink color in this specimen comes from potassium feldspar (orthoclase).
Field identification & locations
Identify in the field by its 'salt and pepper' appearance and hardness (it will scratch glass). This rounded shape indicates it was transported by water or ice far from its original source.
