igneous
Diorite
Intermediate Phaneritic Plutonic Rock - Diorite
AI-generated identification · may be incorrectHardness: 6-7 (Mohs scale), Color: 'Salt and pepper' (mottled black/dark green and white), Luster: Dull to sub-vitreous, Crystal Structure: Phaneritic (visible crystals), Specific Gravity: 2.8-3.0.
Identified More igneous →
Explore Diorite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs scale), Color: 'Salt and pepper' (mottled black/dark green and white), Luster: Dull to sub-vitreous, Crystal Structure: Phaneritic (visible crystals), Specific Gravity: 2.8-3.0.
Formation & geological history
Formed by the slow cooling of magma beneath the Earth's surface in volcanic arcs and mountain building regions (subduction zones). Likely Mesozoic to Cenozoic in age depending on the tectonic setting.
Uses & applications
Used as crushed stone for road construction, base material in building, and sometimes as dimension stone for countertops or monuments when it is aesthetic enough to be polished.
Geological facts
Diorite was used by ancient civilizations, such as the Babylonians and Egyptians, for statues and inscriptions because it is extremely hard and durable; the Code of Hammurabi was inscribed on a diorite stele.
Field identification & locations
Identified by its phaneritic texture with roughly equal amounts of light plagioclase feldspar and dark minerals like hornblende or biotite. Frequently found in batholiths and mountain ranges like the Andes.
