Călx, n.

n.; Eng. pl. CĂLX'ĒS; Lat. pl. CĂL'CES. [Lat. calx, limestone, A.-S. calc, cealc, allied to Gr. χαλίξ, -ικος, small stone, gravel. See CHALK.] (Chem.) The substance of a metal or mineral which remains after being subjected to calcination or combustion by heat, and which is, or may be, reduced to a fine powder.

Metallic calxes are now called oxides.