World English Dictionary
opal (ˈəʊpəl)
an amorphous, usually iridescent, mineral that can be of almost any colour, found in igneous rocks and around hot springs. It is used as a gemstone. Composition: hydrated silica. Formula: SiO2.nH2O
[C16: from Latin opalus, from Greek opallios, from Sanskrit upala precious stone]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Explore Dictionary.com
Previous Definition: opal-glass
Next Definition: opalesce
Words Near: opal-like
More from Thesaurus.com
Synonyms and Antonyms for opal-like
More from Reference.com
Search for articles containing opal-like
More from Dictionary.com Translator
Dictionary.com Word FAQs

Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature