ardennite

ardennite

[är′den‚īt]
(mineralogy)
Mn5 Al5(VO4)(SiO4)5(OH)2·2H2O A yellow to yellowish-brown mineral consisting of a hydrous silicate vanadate and arsenate of manganese and aluminum.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.