Verdigris; the green or bluish-green crystalline coating that forms on copper or bronze when exposed to air and moisture.
From Latin aerugo, meaning verdigris, derived from aes (copper). This term preserves the original Latin name for the oxidized copper compounds that form the distinctive green patina.
Aerugo was such a valuable pigment in ancient times that wealthy Romans kept aerugo deposits as treasures—the green pigment was used in paintings and cosmetics, making weathered copper not waste but a prized resource.
Complete word intelligence in one call. Free tier — 50 lookups/day.