·noun ·Alt. of Yttro-tantalite.
·noun A mineral of a black color, submetallic luster, and high specific specific gravity. It is a ni...
Webster's Dictionary of the English Language
·noun A mineral of a violet-blue color, inclining to gray and white. It is a hydrous fluoride of cer...
·noun A tantalate of uranium, yttrium, and calcium, of a brown or black color. ...