igneous
Diorite
Intermediate plutonic igneous rock
Hardness: 6-7 on Mohs scale. Color: Salt-and-pepper appearance due to a mix of light-colored plagioclase feldspar and dark-colored minerals like hornblende and biotite. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained, visible crystals). Specific gravity: 2.7-2.9.
- Hardness
- 6-7 on Mohs scale
- Luster
- Vitreous to dull
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Physical properties
Hardness: 6-7 on Mohs scale. Color: Salt-and-pepper appearance due to a mix of light-colored plagioclase feldspar and dark-colored minerals like hornblende and biotite. Luster: Vitreous to dull. Crystal structure: Phaneritic (coarse-grained, visible crystals). Specific gravity: 2.7-2.9.
Formation & geological history
Formed from the slow cooling of magma beneath the Earth's surface, having an intermediate composition between granite and gabbro.
Uses & applications
Used in construction, as crushed stone for road building, and as dimension stone for building facades and monuments.
Geological facts
Famous historically as 'Inca stone', diorite was widely used by ancient civilizations like the Incas for architecture and stonework due to its extreme toughness and resistance to weathering.
Field identification & locations
Can be identified in the field by its distinct speckled black-and-white appearance lacking quartz. Commonly found in subduction zone mountain ranges and volcanic arcs.
