Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Shakud is a billon of gold and copper (typically 4% Gold, 96% Copper), mostly designed for its beautiful dark blue-purple patina. It was historically used in Japan to decorate katana fittings such as tsuba and kozuka. When it was introduced to the West in the mid-19th century, it was thought to be previously unknown outside Asia, but recent studies have suggested close similarities to certain decorative alloys used in ancient Egypt, Greece, and Rome. Modern jewelry artisans have revived the use of shakud as a striking design element, especially for the technique of mokume-gane. Shakud is sometimes used as a general term for damascened decorative objects of Japanese origin. These are also widely known in the West as Amita damascene, from the name of a 20th-century manufacturer of such items for export.