Also found in: Encyclopedia, Wikipedia.
A steel-gray mineral, chiefly Bi2Te2S.
[German Tetradymit, from Late Greek tetradumos, fourfold (from the double twin crystals in which it usually is found) : Greek tetra-, tetra- + didumos, double; see dwo- in Indo-European roots.]
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 grey metallic mineral consisting of a telluride and sulphide of bismuth. Formula: Bi2Te2S
[C19: from Late Greek tetradumos fourfold, from Greek tetra- + didumos double]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014