Definition of "epidote" [ep•i•dote]

• A lustrous yellow, green, or black mineral, Ca2(Al, Fe)3(SiO4)3OH, commonly found in metamorphic rock. (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.

• "The feldspar is decomposed with the resulting formation of epidote, which is quite prominent."
• "Here is nobly born quartz living with a green mineral, called epidote; and they are immense friends."
• "Kata Tjuta, covering about 3,500 ha, comprises 36 steep-sided rock domes of gently dipping Mount Currie conglomerate consisting of phenocrysts of fine grained acid and basic rocks, granite and gneiss in an epidote rich matrix."