n combining form
(Geological Science) (in mineralogy) indicating a particular type of cleavage: plagioclase.
[via French from Greek klasis a breaking, from klan to break]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a combining form used in the names of minerals with a particular cleavage, as specified by the initial element: oligoclase; plagioclase.
[< French < Greek klásis breaking, fracture = kla-, s. of klân to break + -sis -sis]
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