igneous
Likely weathered granite or granitic gneiss
Granite–gneiss; chiefly quartz, feldspar, and mica
AI-generated identification · may be incorrectGray-brown, coarse-grained, dull to slightly sparkling surface with a small bright reflective feldspar/quartz area. Typical hardness is about 6–7 Mohs; no reliable cleavage can be assessed from the photo, and specific gravity is commonly 2.6–2.8.
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Physical properties
Gray-brown, coarse-grained, dull to slightly sparkling surface with a small bright reflective feldspar/quartz area. Typical hardness is about 6–7 Mohs; no reliable cleavage can be assessed from the photo, and specific gravity is commonly 2.6–2.8.
Formation & geological history
Granite crystallizes slowly from magma deep underground; gneiss is its metamorphosed equivalent. Precise age cannot be determined visually. Both are widespread in the Precambrian Canadian Shield and glacial deposits around southern Québec.
Uses & applications
Commonly used as crushed stone, aggregate, building stone, monuments, and landscaping material; ordinary hand specimens have little commercial value.
Geological facts
The rounded shape and brown exterior likely reflect weathering and glacial transport. The bright patch could be quartz or fresh feldspar, but the image cannot distinguish them confidently.
Field identification & locations
At approximately 45.4°N, 73.3°W, glacially transported granite and gneiss are very plausible. Look for interlocking light gray/white grains, pink or white feldspar, translucent quartz, and black mica; a fresh break and hardness/streak tests would improve identification.
