the GNU version of the Collaborative International Dictionary of English
n. Black tourmaline.
The Century Dictionary and Cyclopedia
n. A term used by early mineralogists to embrace a large group of crystallized minerals: later limited to common black tourmalin.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. black tourmaline
Word Usage
"The lowest range above Djidda is calcareous; but its rocks soon change into gneiss, and a species of granite, with schorl in the place of feldspath, accompanied by predominant masses of quartz, and some mica."