igneous
Diorite
Intermediate plutonic igneous rock
AI-generated identification · may be incorrectHardness of 6-7 on the Mohs scale, with a salt-and-pepper appearance due to a mix of dark plagioclase feldspar and light hornblende or biotite. It features a phaneritic, medium-to-coarse-grained crystal structure with vitreous luster.
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Physical properties
Hardness of 6-7 on the Mohs scale, with a salt-and-pepper appearance due to a mix of dark plagioclase feldspar and light hornblende or biotite. It features a phaneritic, medium-to-coarse-grained crystal structure with vitreous luster.
Formation & geological history
Formed through the slow cooling of magma rich in silica, plagioclase feldspar, and mafic minerals beneath the Earth's crust. Found globally in orogenic belts and continental roots.
Uses & applications
Widely used in construction, dimension stone, landscaping, and as crushed aggregate for road building and monuments.
Geological facts
Diorite is famously hard to carve, leading ancient civilizations like the Maya and Egyptians to use it for sculpting statues and creating vessels. It is chemically intermediate between granite and gabbro.
Field identification & locations
Identify in the field by its distinct speckled black and white texture without the quartz grains typical of granite. Common in mountainous regions and glacial outwash.
