"a metalliferous mineral or rock," especially one worth mining, 12c., a merger of Old English ora "ore, unworked metal" (related to eorþe "earth;" see earth (n.); and cognate with Low German ur "iron-containing ore," Dutch oer, Old Norse aurr "gravel"); and Old English ar "brass, copper, bronze," from Proto-Germanic *ajiz- (source also of Old Norse eir "brass, copper," German ehern "brazen," Gothic aiz "bronze"), from PIE root *aus- (2) "gold" (see aureate). The two words were not fully assimilated till 17c.; what emerged has the regular modern form of ar but the meaning of ora.
"greenish encrustation on old bronze," 1748, from French patine (18c.), from Italian patina. This appears to be from Latin patina "shallow pan, dish, stew-pan" (from Greek patane "plate, dish," from PIE *pet-ano-, from root *pete- "to spread"), but it is uncertain why, as patina was found on many ancient objects other than bronze plates and pans. It was considered to add greatly to the beauty of antique bronzes, hence the sense of "refinement, cultural sophistication" recorded by 1933. Extended by the 1890s to the surface textures of other works of decorative arts.