igneous
Granite (Polished Pebble)
Phaneritic Plutonic Rock (primarily Orthoclase and Quartz)
Hardness: 6-7 Mohs; Color: Pinkish-brown with black and grey speckles; Luster: Vitreous when polished; Crystal Structure: Coarse-grained phaneritic; Cleavage: None (fractures); Specific Gravity: 2.63-2.75
- Hardness
- 6-7 Mohs
- Color
- Pinkish-brown with black and grey speckles
- Luster
- Vitreous when polished
Identified More igneous →
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Physical properties
Hardness: 6-7 Mohs; Color: Pinkish-brown with black and grey speckles; Luster: Vitreous when polished; Crystal Structure: Coarse-grained phaneritic; Cleavage: None (fractures); Specific Gravity: 2.63-2.75
Formation & geological history
Formed from the slow cooling of magma deep beneath the Earth's surface (plutonic). This specimen has been rounded and polished by either river action or a rock tumbler.
Uses & applications
Primarily used in construction (countertops, monuments) and as decorative landscape gravel or polished pocket stones.
Geological facts
Granite makes up a large portion of the Earth's continental crust. The pink color in this specimen is due to the presence of potassium feldspar (orthoclase).
Field identification & locations
Identify by its interlocking crystalline texture and lack of layering. Commonly found in mountainous regions or as river pebbles. Collectors look for unique mineral inclusions like mica or tourmaline.
