igneous
Quartz-bearing granite or granitic pegmatite
Coarse-crystalline granitoid; primarily quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining
AI-generated identification · may be incorrectHardness about 6–7; pale pink, white, gray, and brown; glassy quartz luster with blocky feldspar and flaky mica. Interlocking crystals and irregular fracture are typical; specific gravity roughly 2.6–2.7.
Identified More igneous →
Explore Quartz-bearing granite or granitic pegmatite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6–7; pale pink, white, gray, and brown; glassy quartz luster with blocky feldspar and flaky mica. Interlocking crystals and irregular fracture are typical; specific gravity roughly 2.6–2.7.
Formation & geological history
Formed when silica-rich magma cooled slowly deep in the crust, producing large crystals; likely Precambrian to younger depending on locality. Brown and reddish colors commonly reflect weathering and iron oxidation.
Uses & applications
Used as crushed aggregate, building stone, countertops, monuments, and landscaping rock; attractive pieces may be sold as cabinet specimens. Ordinary hand specimens generally have modest value.
Geological facts
The pink coloration commonly comes from potassium feldspar, while translucent gray areas are quartz. A steel nail usually does not scratch quartz, but can mark softer feldspar or weathered surfaces.
Field identification & locations
Look for visible interlocking quartz, feldspar, and mica rather than layered fabric or rounded pebbles; a fresh broken surface is most diagnostic. Common worldwide in continental shields, mountain belts, and granite plutons.
