Macigno (mā-chēn'yo), n.

noun

(mā-chēn'yo), n. [It. macina, macine, a mill-stone, grinding-stone, from Lat. machina, engine, device. See MACHINE.] (Min.) A kind of silicious sandstone found in Italy. There are two varieties, one of a grayish-yellow color, the other of a bluish-gray color. Dana.