赤しゃく銅どう

noun

shakudo; gold-copper alloy with blue-black patina

A traditional Japanese alloy of copper and a small amount of gold, often treated to develop a rich blue-black or purple-black patina. Used in sword fittings, jewelry, and decorative metalwork.

• この刀かたなの鍔つばは赤しゃく銅どうで作つくられている。

  The tsuba of this sword is made of shakudo.

• 赤しゃく銅どうの独どく特とくな青あお黒ぐろい色いろは、煮に色いろ仕し上あげによって生うまれる。

  The distinctive blue-black color of shakudo is produced through a patination process called niiro finish.