noun
or etching figure
: a marking consisting usually of a minute pit produced by a solvent on the crystal face of a mineral and revealing its molecular structure — usually used in plural
noun
or etching figure
: a marking consisting usually of a minute pit produced by a solvent on the crystal face of a mineral and revealing its molecular structure — usually used in plural
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012