igneous
Granodiorite or Diorite
Granodiorite / Diorite
Hardness: 6-7 on Mohs scale, Color: speckled black and white or gray (salt and pepper appearance), Luster: dull to slightly shiny, Texture: phaneritic (coarse-grained)
- Luster
- dull to slightly shiny, Texture: phaneritic (coarse-grained)
Identified More igneous →
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Physical properties
Hardness: 6-7 on Mohs scale, Color: speckled black and white or gray (salt and pepper appearance), Luster: dull to slightly shiny, Texture: phaneritic (coarse-grained)
Formation & geological history
Formed by slow cooling of magma deep underground (intrusive). Composed mainly of plagioclase feldspar, quartz, hornblende, and biotite.
Uses & applications
Commonly used for crushed stone, construction, landscaping, and sometimes as dimension stone.
Geological facts
Diorite is often called 'salt and pepper' rock due to its speckled appearance. It was used by ancient civilizations for carving and sculpture.
Field identification & locations
Identified by its speckled black and white appearance and lack of foliation. Common in continental crust and mountain-building regions.
