The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Peridotite is a dark-colored, coarse-grained igneous rock believed by many scientists to be the primary rock of the exterior of Earth's mantle. The rock typically forms in volcanic pipes and is forced to the surface from great depths during a volcanic eruption.
Peridotite consists of a dense iron and magnesia mineral called olivine, as well as pyroxenes and a small amount of feldspar. It is a pistachio-green color when fresh, but weathering creates iron oxides that turn it a medium brown. The iron and magnesia-rich rock is the most common host for naturally occurring diamonds. South African diamonds are obtained from a mica-rich form of peridotite called kimberlite. Periodite is also a source of valuable ores and minerals including chromite, platinum, nickel, and precious garnet. In rare instances, individual olivine crystals in periodite are large enough and pure enough to be designated a gem. The resulting gem is a semi-precious mineral called peridot.
Periodite is found worldwide, but particularly in New Zealand.