igneous
Granite Pebble (Pink/Orthoclase Granite)
Granite (rich in Potassium Feldspar / Orthoclase)
Hardness 6-7 on Mohs scale; pinkish-red to salmon color with grains of quartz (clear/grey) and biotite/hornblende (dark flecks); vitreous to dull luster; phaneritic intrusive igneous texture rounded by water erosion; specific gravity 2.63-2.75.
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Physical properties
Hardness 6-7 on Mohs scale; pinkish-red to salmon color with grains of quartz (clear/grey) and biotite/hornblende (dark flecks); vitreous to dull luster; phaneritic intrusive igneous texture rounded by water erosion; specific gravity 2.63-2.75.
Formation & geological history
Formed from slow cooling of silica-rich magma deep underground (plutonic environment), allowing visible mineral grains to crystallize. This water-worn pebble was eroded from a larger batholith and rounded by river or wave action.
Uses & applications
Commonly collected as river stones or beach pebbles; polished for decorative landscaping, aquariums, and rock tumbling; larger deposits are mined for dimension stone, countertops, and road aggregate.
Geological facts
Pink granite gets its distinctive color from abundant potassium feldspar (orthoclase or microcline). Water action smoothed this pebble over hundreds to thousands of years, wearing away sharp edges.
Field identification & locations
Easily identified by its speckled pink, quartz-grey, and black mineral pattern and rounded cobble shape. Very common on beaches, stream beds, and glacial till near granitic bedrock regions like the Great Lakes or Canadian Shield.
