(IDEX Online) - A one-off ring set with 291 diamonds from Australia's iconic Argyle mine is being offered for sale, with a US$590,000 price tag.It features a pair of matching 0.75 carat oval modified brilliant fancy vivid pink diamonds (SI2/SI1), and 285 round brilliant cut fancy purplish pink and fancy intense purplish pink diamonds (total weight 2.11 carats). There are also four tiny (0.03 carat) blue diamonds. All the stones are from the Rio Tinto-owned Argyle mine, source of the world's highest-quality pink diamonds, which closed in November 2020.The ring, made of Australian gold, is described as "a bespoke handcrafted piece inspired by the Western Australian landscape".It was designed by the Perth Mint, Australia's official bullion mint, in collaboration with Australian jeweler John Glajz.