igneous
Pink Granite / Gneiss Pebble
Quartz-Feldspar Granitic Rock
Hardness: 6-7 on Mohs scale. Color: reddish-pink, orange-brown, greyish-brown. Luster: dull to vitreous. Grain size: medium to coarse. Contains visible pink potassium feldspar and quartz grains.
- Hardness
- 6-7 on Mohs scale
- Color
- reddish-pink, orange-brown, greyish-brown
- Luster
- dull to vitreous
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Physical properties
Hardness: 6-7 on Mohs scale. Color: reddish-pink, orange-brown, greyish-brown. Luster: dull to vitreous. Grain size: medium to coarse. Contains visible pink potassium feldspar and quartz grains.
Formation & geological history
Formed deep underground by the slow cooling and crystallization of silica-rich magma (granite) or altered under high heat and pressure (gneiss), then rounded and smoothed by stream or glacial erosion.
Uses & applications
Used as decorative garden river rock, landscaping material, crushed stone for construction, and as an educational or amateur collector pebble.
Geological facts
The distinct reddish-pink color comes from orthoclase or microcline feldspar enriched with iron impurities. Water and stream action often round these rocks into smooth cobbles over thousands of years.
Field identification & locations
Identify by looking for intergrown coarse pink feldspar and glassy grey/white quartz grains. Commonly found in glaciated regions, riverbeds, and gravel pits across North America and Europe.
