When shopping for authentic Japanese jewelry -- rings, necklaces, earrings, bracelets, etc. -- you may come across a special type of metal known as shakudō. Featuring a light brass or bronze color, it's become a popular metal used by Japanese jewelry artisans. Before it was used in jewelry, however, shakudō was used in the manufacturing of high-quality traditional Japanese swords.
What Is Shakudō?
As shown in the photo above, shakudō is a unique metal that resembles bronze and brass. In terms of composition, it's comprised of approximately 4% to 10% gold and 90% to 96% copper. While most shakudō features this distinct color, metalworkers can create a darker tone using a special heating process known as rokusho.
The name "shakudō" translates from the Japanese language meaning "red and copper." Again, most shakudō feature this characteristic color, but metalworkers often use different techniques to achieve lighter or darker tones. The true defining characteristic of shakudō is its composition of gold and copper, which provides both aesthetic and strength.
Shakudō in Traditional Japanese Swords
Traditional Japanese swords produced during the country's feudal period were typically made of high-carbon steel. Tamahagane steel, for example, featured a carbon content of up to 4.5%. Swordsmiths discovered that adding carbon steel made their blades stronger and more durable, protecting against damage and, ultimately, prolonging the life of the blade.
However, Japanese swordsmiths used other metals to produce their swords, including shakudō. Shakudō wasn't used to make blades. Rather, it was used to make the tsuba. This meant swordsmiths only needed a small amount of copper and gold. If the entire blade was produced of shakudō, it would require a substantial amount of resources to make.
As you may already know, the tsuba is the hand guard found on many traditional Japanese swords. Typically featuring a circular- or square-shaped design, it protected the samurai warrior's hands from accidental self-injury. Because it wasn't exposed to direct blows like the blade, swordsmiths could use other metals to produce the tsuba. In addition to shakudō, they would often produce tsubas using iron, steel, brass, copper and various alloys.
Today, shakudō is typically used in Japanese jewelry, though a few sword companies continue to use it to make their tsubas. With that said, the high cost of gold has limited its utility in real-world applications. Swordsmiths and jewelry artisans now use cheaper metals in their respective craft to save money.