igneous
Granite
Phaneritic intrusive igneous rock (primarily SiO2)
Hardness: 6-7 on Mohs scale; Color: Pinkish-red, white, and black; Luster: Dull to vitreous; Structure: Coarse-grained (phaneritic); Composition: Orthoclase feldspar, quartz, and hornblende/biotite.
- Hardness
- 6-7 on Mohs scale
- Color
- Pinkish-red, white, and black
- Luster
- Dull to vitreous
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Physical properties
Hardness: 6-7 on Mohs scale; Color: Pinkish-red, white, and black; Luster: Dull to vitreous; Structure: Coarse-grained (phaneritic); Composition: Orthoclase feldspar, quartz, and hornblende/biotite.
Formation & geological history
Formed by the slow crystallization of magma below Earth's surface. This specimen shows significant water-tumbled rounding, indicating it was likely transported by a river or stream. Geologically, specimens like these can range from hundreds of millions to billions of years old.
Uses & applications
Large-scale construction, countertops, monuments, and as crushed stone for road base. Pebbels like this are used in landscaping and aquarium decor.
Geological facts
Granite makes up a large portion of the Earth's continental crust. The pink color in this specific pebble comes from potassium-rich feldspar (orthoclase).
Field identification & locations
Identified by its 'salt and pepper' or mottled appearance with visible interlocking crystals. Common in glacial till, riverbeds, and mountainous regions. For collectors, look for the distinct pink feldspar grains contrasting with darker minerals.
