Also found in: Encyclopedia, Wikipedia.
A white or colored crystalline mineral, a variety of willemite, in which the zinc is partly replaced by manganese.
[After Gerard Troost (1776-1850), Dutch-born American geologist.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
(Minerals) a reddish or greyish mineral that is a variety of willemite in which some of the zinc is replaced by manganese
[C19: named after Gerard Troost (died 1850), US geologist]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014