Derived from the Latin word for the colour blue (sapphirus), sapphires are believed to be the gems of the heavens. The saturation of the blue hue is key to determining the value of this coveted gemstone, one of the big three alongside rubies and emeralds.
“Invest in untreated sapphires of high quality and of Kashmir or Burmese origin, where most the world’s most beautiful and highly valued sapphires were mined,” says Vickie Sek, chairman, Jewellery Asia, Christie’s auction house.
Kashmir sapphires can be traced back to 1881, when a landslide in the northwestern Himalayas revealed sapphire-bearing rocks. By 1887, Kashmir’s first sapphire mine had been exhausted and production ceased. As a result, gem-quality Kashmir sapphires are now extremely rare.
Kashmir sapphires are characterised by their luminous blue and silken transparency. Sought-after sapphires have not been mined commercially since the start of the 20th century, driving prices up.
At the Hong Kong Magnificent Jewels auction by Christie’s in May, a pair of earrings with a 10.27ct and a 10.01ct Burmese no heat blue sapphire went under the hammer for US$320,513, while a 26.41ct Kashmir no heat sapphire brooch cost US$4.33 million.
“Kashmir sapphires normally have a rich, cornflower blue or velvety blue colour, with an overall soft and velvety appearance,” says Christie’s Sek.
While the term sapphire is usually associated with the blue variety of the mineral corundum, they come in almost any colour of the spectrum “except red, which is the colour variety of corundum called ruby”, says Daniel Nyfeler, managing director of Gübelin Gem Lab in Switzerland.
“A deep saturated royal blue is the most coveted sapphire colour, occasionally found in different places including [Myanmar] and Madagascar. The sapphires from Kashmir, achieving record prices at auctions, show a different type of blue, also very saturated, but brighter, and of a velvety, hazy softness, sometimes referred to as ‘sleepiness’. Induced by microscopically small particles arranged in bands and blocks, Sri Lankan and Madagascan sapphires can also display this phenomenon,” explains Nyfeler.
Courtesy - scmp.com
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