igneous
Granitic Pegmatite
Granite (with coarse-grained Quartz, Feldspar, and Mica components)
Hardness: 6-7 (Mohs scale); Color: Mottled white, gray, and pink/tan with dark flecks; Luster: Vitreous to pearly; Crystal structure: Phaneritic (large, visible crystals); Cleavage: Perfect in feldspar and mica inclusions; Specific gravity: 2.6-2.7
- Hardness
- 6-7 (Mohs scale)
- Color
- Mottled white, gray, and pink/tan with dark flecks
- Luster
- Vitreous to pearly
Identified More igneous →
Explore Granitic Pegmatite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs scale); Color: Mottled white, gray, and pink/tan with dark flecks; Luster: Vitreous to pearly; Crystal structure: Phaneritic (large, visible crystals); Cleavage: Perfect in feldspar and mica inclusions; Specific gravity: 2.6-2.7
Formation & geological history
Formed from the slow cooling of magma deep within the Earth's crust, allowing large crystals to grow. Typically found in Plutonic environments and ancient continental shields.
Uses & applications
Used in construction as crushed stone, architectural facades, and countertops. Also a source of industrial minerals like quartz and mica.
Geological facts
Pegmatites are known for containing the largest crystals of any rock type on Earth. This specimen shows a mix of milky quartz and alkaline feldspar.
Field identification & locations
Identify in the field by its coarse, 'salt and pepper' crystalline texture and extreme hardness (cannot be scratched by a steel knife). Commonly found in mountain ranges and glacial till.
