zinc-spinelhttp://www.oed.com/dictionary/zinc-spinel_n%3Ftab%3Dmeaning_and_usezinc-spinel, n.
First published 1921; not fully revised

zinc-spinelnoun

  1. 1868–
    = gahnite n. (Dana Min. 1868).

Originally published as part of the entry for zinc, n.

zinc, n. was first published in 1921; not fully revised.