Rokushō

Rokushō(緑青) is a traditional Japanese compound for inducing patination in decorative non-ferrous metals, especially several alloys which are nearly unknown outside Japan. Shakudō, an alloy of copper and gold, becomes dark blue-violet; shibuichi, an alloy of fine silver and copper in a higher percentage than sterling, turns misty aquamarine; and kuromido dark coppery black. These alloys are becoming increasingly popular in high-end artistic jewelry, especially in bi-metals (a layer of the alloy fused to another metal such as sterling). Rokushō was generally used to patinate all types of mokume-gane as well. Although other patination agents can be used on these metals, some artisans prefer the rich colors achieved through traditional Rokushō.