D defs.my
Entry 1 sense Webster, 1913

Heavy spar

/hĕv'-ē spär/ · Heav·y spar · IPA
01 Native barium sulphate or barite, -- so called because of its high specific gravity as compared with other non-metallic minerals.
  1. 1.
    Native barium sulphate or barite, -- so called because of its high specific gravity as compared with other non-metallic minerals.(Min.)