What does 916 gold mean?
916 refers to fineness: 916 parts of pure gold per 1,000 parts of metal, or approximately 91.6% gold purity. It is the millesimal equivalent of 22 karat (22 ÷ 24 = 0.9166…), so "916 gold" and "22K gold" describe the same alloy. The remaining 8.4% is typically copper and silver, added to make the metal hard enough for daily wear.
Japanese jewellery is typically K18 (75% gold), with pure K24 reserved for investment items and ceremonial pieces. Purity is stamped as K18 or K24 together with the maker's mark, and major retailers publish a daily gold price in yen per gram.