K22 is the Japanese marking convention for 22-carat gold, indicating an alloy of 916 parts gold per 1,000, equivalent to the international 22-carat or 916 fineness used in South Asian and Middle Eastern markets. K22 is less common in Japanese fine jewellery than K18, but is used for traditional, ceremonial and gift items where a softer, more saturated yellow colour is preferred.

Marking and alloy

The K22 mark follows the same self-applied Japanese marking convention as K18, K20 and K24. The alloy is typically gold with small additions of copper and silver to produce the deep yellow colour characteristic of South Asian 22-carat gold. The Mohs hardness of K22 is lower than K18 because of the higher fine-gold content, which makes the metal more vulnerable to scratching and bending in everyday wear. K22 is therefore generally not used in Japanese diamond bridal jewellery, where structural rigidity is required, but is well suited to chains, plain bands, ear studs and presentation items.

Use in Japan

K22 jewellery is produced in Japan principally for three markets. First, traditional ceremonial gifts, including small commemorative gold leaves, plates and traditional auspicious motifs, where the softer colour and higher gold content carry cultural weight. Second, exports to South Asian and Middle Eastern markets, where 22-carat gold is the local fineness standard for bridal jewellery. Third, the small but persistent Japanese market for South Asian-influenced jewellery, particularly in cities with significant Indian and Sri Lankan diaspora populations.

Trade significance

For the international trade K22 is interchangeable with European 916 markings under the FTC Jewelry Guides and equivalent international conventions, although the marking is sometimes encountered alongside or instead of the international 916 mark on Japanese-produced exports. The metal's softness and high gold content make it primarily a content-and-investment fineness rather than a structural fineness for Japanese fine jewellery.