| Share


obsidian (ŏbsĭdˈēən) [key], a volcanic glass, homogeneous in texture and having a low water content, with a vitreous luster and a conchoidal fracture. The color is commonly black, but may be some shade of red or brown, and cut sections sometimes appear to be green. Like other volcanic glasses, obsidian is a lava that has cooled too quickly for the contained minerals to crystallize. In chemical composition it is rich in silica and similar to granite. It is favored by primitive peoples for knives, arrowheads, spearheads, and other weapons and tools.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on obsidian from Infoplease:

See more Encyclopedia articles on: Mineralogy and Crystallography

Premium Partner Content
HighBeam Research
Documents Images and Maps Reference
(from Newspapers, Magazines, Journals, Newswires, Transcripts and Books)

Research our extensive archive of more than 80 million articles from 6,500 publications.

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.

24 X 7

Private Tutor

Click Here for Details
24 x 7 Tutor Availability
Unlimited Online Tutoring
1-on-1 Tutoring