Having good cleavage. Used of minerals.
[German Spah, Spath, spar (from Middle High German spāt) + -ic.]
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) (of minerals) resembling spar, esp in having good cleavage
[C18: from German Spat, Spath spar3; related to Old High German spān chip; see spoon]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014