Mix copper with gold and you end up with a metal more elegant than either: rose gold. Its popularity has waxed and waned through the generations: it was in vogue in 19th-century Russia, when Carl Fabergé incorporated it into designs for his jewelled eggs, and in the 1920s, when Cartier started to make trinity bands (also known as Russian wedding rings). It is now so fashionable that it has spread from jewellery to beauty and accessories – even Apple makes an iPhone in the colour.
The ratio of copper to gold determines the shade. Some jewellers use more gold, to produce a delicate hue, like the pale pink of a primrose bud. Roberto Coin, an Italian designer who created the bangle shown above, tips the balance towards copper, to create a shade that puts him in mind of a peach flower in full bloom.