Greisen
/ˈɡraɪ.zən/noun
A coarse-grained, altered granite composed mainly of quartz and mica, often containing topaz or tourmaline.
Did you know?Greisen is a real geological term from German mining language, and it refers to a rock transformed by late-stage hydrothermal fluids—basically stone that has been “re-scripted” after the original magma cooled.
Etymological Timeline
German mining language
German
Greisen
“Altered granite or quartz-mica rock associated with tin and other ore deposits”
19th Century
English
greisen
“Borrowed geological term used by English-speaking mineralogists”
Modern English
English
greisen
“A coarse-grained altered granite rich in quartz and mica”
Proto-Indo-European
PIE
*ghrei-
“To rub, grind, or break into small pieces”