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


Sliding Rocks
Sliding Rocks Mystery: What causes these rocks to slide across a Death Valley playa?
Coal
Coal Through a Microscope: Coal is more than a black rock. It's THE most interesting rock.
US Gemstones
United States Gemstones: A diversity of gemstones are produced in the United States.
Diamonds from Coal
Biggest Misconception: Lots of people think that diamonds form from coal. Not True!
Gemstones
Gemstones: Fantastic images and articles about colored stones and diamonds.
largest volcano
The Largest Volcanoes on Earth might not be the ones that you are thinking about.
Diamonds
Diamonds: Learn about the properties of diamond, its many uses and diamond discoveries.
The Largest Tsunami!
The Largest Tsunami! The tsunami with the highest run-up was in Lituya Bay, Alaska.


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



© 2005-2014 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.