McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams

Home » Rocks » Igneous Rocks » Diorite

Diorite


What is Diorite?



Diorite is a coarse-grained, intrusive igneous rock that is intermediate in composition between granite and gabbro. It’s composition is very similar to the fine-grained extrusive rock known as andesite.

Diorite is composed primarily of plagioclase feldspar, amphibole, and pyroxine minerals with small amounts of biotite mica. It typically contains very little quartz.

When identifying diorite look for a rock that as abundant white and dark minerals - a “salt and pepper” appearance. With a hand lens look for the cleavage faces of plagioclase feldspar intersecting at oblique angles. Also, look for vitreous cleavage faces on the dark amphibole minerals.


More Igneous Rocks
  Peridotite
  Pumice
  Scoria
  Pegmatite
  Obsidian
  Gabbro
  Granite
  Basalt



Find it on Geology.com




More from Geology.com


What Are Meteorites?
What Are Meteorites? Rocks which were once part of planets or large asteroids.
Mars Meteorites
Mars Meteorites: Interesting iron meteorites found on Mars by NASA rovers.
Yosemite Glaciers
Yosemite Glaciers: There are two active glaciers in Yosemite - but they are slowly melting away.
What Is The Moho?
What Is The Moho? Learn about the interior of the Earth and the Mohorovicic Discontinuity.
zoisite
Zoisite is a diverse gem. Tanzanite, thulite and anyolite are three of its gem varieties.
Who Owns The Arctic?
Who Owns The Arctic? USGS estimates that 25% of all new oil & gas will be found in the Arctic.
Corundum
Corundum is the third hardest mineral. It is also the mineral of ruby and sapphire.
Ametrine
Ametrine is a bicolor quartz (amethyst + citrine) and a gemstone of growing popularity.


Diorite
Diorite: The specimen shown is about two inches (five centimeters) across.



© 2005-2015 Geology.com. All Rights Reserved.
Images, code and content of this website are property of Geology.com. Use without permission is prohibited. Pages on this site are protected by Copyscape.