aquaregia

aqua re·gi·a (rēʹjē-ə, rēʹjə) n.

A corrosive, fuming, volatile mixture of hydrochloric and nitric acids, used for testing metals and dissolving platinum and gold. Also called nitrohydrochloric acid.

  [New Latin aqua rēgia: Latin aqua, water + Latin rēgia, feminine of rēgius, royal (because it dissolves gold, the “royal metal”).]

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