greisen

[grahy-zuh n]

noun

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. 2019

Examples from the Web for greisen

Greisen is closely connected with schorl rock both in its mineralogical composition and in its mode of origin.
Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5|Various
Greisen occurs typically in belts or veins intersecting granite.
Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 5|Various

British Dictionary definitions for greisen

greisen

noun

a light-coloured metamorphic rock consisting mainly of quartz, white mica, and topaz formed by the pneumatolysis of granite

Word Origin for greisen

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