igneous
Diorite
Diorite (Intermediate intrusive igneous rock)
Hardness: 6-7 on Mohs scale. Color: Salt-and-pepper (speckled black and white). Luster: Phaneritic (crystalline). Crystal structure: Monoclinic/Triclinic minerals. Specific gravity: 2.85-3.0.
- Hardness
- 6-7 on Mohs scale
- Color
- Salt-and-pepper (speckled black and white)
- Luster
- Phaneritic (crystalline)
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Salt-and-pepper (speckled black and white). Luster: Phaneritic (crystalline). Crystal structure: Monoclinic/Triclinic minerals. Specific gravity: 2.85-3.0.
Formation & geological history
Formed by the slow cooling of magma beneath the Earth's surface in volcanic arcs and mountain-building zones. Often found above subduction zones.
Uses & applications
Commonly used as a base material in construction of roads and buildings. When polished, it is used as dimension stone for countertops and floor tiles. Historically used for sculpture due to its extreme durability.
Geological facts
The famous Code of Hammurabi, one of the oldest deciphered writings of significant length in the world, was inscribed onto a 7-foot tall diorite stele.
Field identification & locations
Identify by its phaneritic (visible crystals) coarse-grained texture and balanced speckled appearance. Unlike granite, it lacks significant quartz and has little to no pink potassium feldspar. Commonly found in roots of mountain ranges like the Andes.
