- a hydrothermally altered rock of granitic texture composed chiefly of quartz and mica, common in the tin mines of Europe.
Origin of greisen
Borrowed into English from German around 1875–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for greisen
Greisen occurs typically in belts or veins intersecting granite.
Greisen is closely connected with schorl rock both in its mineralogical composition and in its mode of origin.
- a light-coloured metamorphic rock consisting mainly of quartz, white mica, and topaz formed by the pneumatolysis of granite
C19: from German, from greissen to split
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012