Definition of "trichroism" []

• The property possessed by certain minerals of exhibiting three different colors when viewed from three different directions under white lights. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It displays a rare property called trichroism, displaying three colors sapphire blue, ruby red and amethyst purple, depending on which of its three axes you look at."