zinc-sparhttp://www.oed.com/dictionary/zinc-spar_n%3Ftab%3Dmeaning_and_usezinc spar, n.
First published 1921; not fully revised

zinc sparnoun

  1. 1796–
    An old name for native zinc carbonate (= calamine n., smithsonite n. 2).
    1. 1796
      Zinc Spar.
      R. Kirwan, Elements of Mineralogy (ed. 2) vol. II. 236

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

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