Shakudo

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What is Shakudo?

The Japanese are well known for their exceptional skills in metallurgy, as noted by their highly durable and intrinsically beautiful blades that are now known all throughout the world. However, the Japanese are not only experts in the craft of bladesmithing, as they are also highly skilled in the creation of unique and highly ornate alloys that are used for ornamentation. Of the most notable is shakudo[1a], a specialized alloy of gold and copper that is used as a decorative accessory. Shakudo is simply nothing more than an alloy of gold and copper, usually composed of a very minute amount of gold mixed with a higher amount of copper to create a rich dark-reddish metal which is then coated with a special concoction known as rokusho, which helps darken it to a rich purplish to black patina[1] .

Developed sometime during the 13-1400s, shakudo was once employed as fittings for daisho[2] or sword sets. Due to its inherent beauty, it could either be polished into a rich coppery sheen, or patinated to a dark, purple coloration that would often contrast areas that were expressly polished to show strikingly ornate detail in a technique referred to as mokume-gane[3] . Though commonly employed to create fittings for samurai katana[4] such as the tsuba[5] (hand guard), menuki[6] (handle amulet), and kozuka[7] (blade handle of kogatana[8] daggers) it was also used to create tiny pieces of jewelry usually given as gifts, or in the creation of blessed amulets given as gifts (omamori[9] ).

To create an alloy of shakudo, some 94-98% of copper is combined with a little gold and is then cast and tooled by hand into highly ornate pieces. Shakudo containing slightly more significant amounts of gold (4-10%) are pricier than typical shakudo. It can be left as is, in which case it will never develop any kind of patina, as the gold helps prevent copper from oxidizing. However, full-fledged shakudo are coated with a special formulation that helps to turn it into a rich black color. Rokusho can be made from a combination of copper acetate, calcium carbonate, sodium hydroxide, copper sulfate and water. Depending on the artist or the school that creates shakudo, this mixture may vary, with some patinating solutions being kept as closely guarded artisan secrets[10].

The art of shakudo was later introduced to the west sometime during the middle of the 19th century, where it was advertised to be a type of alloy known only in Japan. This erroneous idea was furthered by referring to it as Amita damascene, comparing it to the remarkable metalworking technique known as damascening. This was an erroneous marketing ploy however, as damascene and shakudo are two entirely different metalworking techniques. Because gold is scarce in Japan, shakudo were very pricey and were often reserved only for the wealthiest of feudal lords. When it was introduced to the west, it became very popular, often being used to as inlays for a number of different objects. Due to the wide availability of gold in the west, shakudo was relatively cheaper compared to other gold alloys. Antique shakudo however can fetch very high prices in the market, as they are rare and are considered collector’s items. Most antique examples of shakudo are Japanese sword fittings or tiny pieces of jewelry. Nowadays, the practice of shakudo is no longer limited to Japanese craftsmen, as examples of shakudo made non-Japanese artisans are now replete in the market.

Shakudo - References:

[1a] http://www.oldcopper.org/shakudo.htm
[1b] http://en.wikipedia.org/wiki/Rokush%C5%8D
[2] http://en.wikipedia.org/wiki/Daisho
[3] http://en.wikipedia.org/wiki/Mokume-gane
[4] http://en.wikipedia.org/wiki/Katana
[5] http://en.wikipedia.org/wiki/Tsuba
[6] http://www.nihonzashi.com/menuki.aspx
[7] http://www.ncjsc.org/gloss_kozuka.htm
[8] http://www.ncjsc.org/gloss_kogatana.htm
[9] http://en.wikipedia.org/wiki/Omamori
[10] http://www.ganoksin.com/borisat/nenam/shakudo.htm

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