Typically these metals are silver and copper. Rose gold, obtained by adding copper, became very popular in the 19th century while white gold, a mix of gold and palladium or silver, became fashionable in the 1920s. Both are now staples of the jewelry trade. But modern jewelers are experimenting with new tints, ranging from purple and blue to chocolate and black.
The London designer Hannah Martin has used black and red gold in her collections for several years. Her black gold jewelry items are 18-karat pure gold coated with a plating of black rhodium. Nathan Morse, the managing director of Hannah Martin, says the intention is to “flip the concept of luxury almost on its head — the notion that only the wearer knows its true worth is the point here.”
The secret of making purple gold is believed to have been first discovered by the ancient Egyptians, but it is still something of a novelty in the jewelry world. “In the past, purple gold could be obtained but was a bit unstable and difficult to perfect,” said Kean Ng, business director at Aspial-Lee Hwa Jewellery in Singapore. Aspial-Lee Hwa was the first company to market purple gold jewelry, in 2000, after buying the patent rights from a professor of metallurgy at Singapore Polytechnic. The color is obtained by mixing 80 percent pure gold with palladium and a secret blend of other metals. Read the whole story in the IHT