igneous
Granite Pebble (Unakite / Feldspar-rich Granite)
Granite (rich in Potassium Feldspar and Epidote)
Hardness: 6-7 on the Mohs scale. Color: Pinkish-red (orthoclase feldspar) with green (epidote/chlorite) and gray/clear quartz inclusions. Luster: Dull to vitreous. Cleavage: Poor in mass rock, distinct in individual feldspar grains.
- Hardness
- 6-7 on the Mohs scale
- Luster
- Dull to vitreous
Identified More igneous →
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Physical properties
Hardness: 6-7 on the Mohs scale. Color: Pinkish-red (orthoclase feldspar) with green (epidote/chlorite) and gray/clear quartz inclusions. Luster: Dull to vitreous. Cleavage: Poor in mass rock, distinct in individual feldspar grains.
Formation & geological history
Formed from the slow cooling and crystallization of felsic magma deep beneath the Earth's surface (plutonic environment). Smooth, rounded shape indicates transport and weathering by water in rivers or along lake shores.
Uses & applications
Crushed stone for road beds and construction, architectural slabs when found in large blocks, or tumbled for lapidary and decorative pebble collections.
Geological facts
Red or pink granite gets its characteristic color from potassium-rich orthoclase feldspar. Small green patches often signal hydrothermal alteration into epidote, similar to the rock unakite.
Field identification & locations
Identify by its coarse-grained phaneritic texture featuring intergrown pink feldspar, grey quartz, and greenish minerals. Commonly found in glaciated riverbeds, beaches, and mountainous igneous zones.
