igneous
Granite Pebble
Intrusive Igneous Rock (Felsic to Intermediate)
Hardness of 6-7 on the Mohs scale, composed mainly of quartz, alkali feldspar, plagioclase, and biotite mica. Color varies with pink, grey, and black speckles. Luster is typically dull to vitreous on fractured crystal faces. Specific gravity ranges from 2.65 to 2.75.
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Physical properties
Hardness of 6-7 on the Mohs scale, composed mainly of quartz, alkali feldspar, plagioclase, and biotite mica. Color varies with pink, grey, and black speckles. Luster is typically dull to vitreous on fractured crystal faces. Specific gravity ranges from 2.65 to 2.75.
Formation & geological history
Formed from the slow crystallization of magma far beneath the Earth's surface, typically over millions of years, followed by weathering, erosion, and water transport into a smooth pebble shape.
Uses & applications
Used in construction, monumental stone, architectural facings, countertops, and landscaping materials.
Geological facts
Granite is the most common intrusive rock of Earth's continental crust. Its interlocking crystal structure makes it extremely durable and resistant to weathering.
Field identification & locations
Easily identified in the field by its distinct speckled appearance containing interlocking crystals of light-colored quartz and feldspar mixed with dark minerals like biotite. Found worldwide in riverbeds, glacial tills, and beaches.
