Definitions

1. noun

A rare mineral, barium calcium phosphate, Ba2Ca(PO4)2.

“The geologist discovered a rare specimen of joannite in the abandoned mine.”

2. proper noun

A mineral named after Joanne Morgan, the wife of American mineralogist Charles Palache.

“The researchers credited the discovery of joannite to the dedication of Charles Palache and his wife, Joanne.”