Is Obsidian Intrusive or Extrusive?

Answer

Obsidian is considered to be a black extrusive, igneous rock. It is characterised by a shiny surface and it is created by volcanic gas. Obsidian comprises of high contents of silica.
Q&A Related to "Is Obsidian Intrusive or Extrusive?"
intrusion - intrusion is when magma cools down inside Earth. extrusion - extrusion is when lava cools down on Earth.
http://wiki.answers.com/Q/Are+obsibian+intrusive+o...
Obsidian is an extrusive rock rather than intrusive. Extrusive rocks are formed by
http://www.chacha.com/question/how-is-obsidian-an-...
in·tru·sion (n-trzhn) n. 1. The act of intruding or the condition of being intruded on. 2. An inappropriate or unwelcome addition. 3. Law Illegal entry upon or appropriation
http://answers.yahoo.com/question/index?qid=200804...
Extrusive formations flow out of the Earth onto the surface of the planet, such as the basalt deposits of South America. Intrusive formations occur when magma does not break through
http://www.webanswers.com/science/what-is-the-diff...
About -  Privacy -  Careers -  Ask Blog -  Mobile -  Help -  Feedback  -  Sitemap  © 2014 Ask.com