• Jewels : The Geneva Sale auction at Christies

    Sale 1371

    Jewels : The Geneva Sale

    18 November 2009, Geneva

  • Lot 196

    A VERY RARE COLOURED DIAMOND RING

    Price Realised  

    A VERY RARE COLOURED DIAMOND RING
    Set with a square-cut fancy intense green diamond weighing 4.42 carats to the baguette-cut diamond shoulders and 18k white gold hoop with diamond detail, ring size 6
    Accompanied by report no. 1102900161 dated 22 July 2009 from the GIA Gemological Institute of America stating that the diamond is Fancy Intense Green colour, VS2 clarity


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    A naturally coloured green diamond is a true rarity of nature. Following red, and ahead of even blue and orange, green is one of the rarest colours in which to find naturally occurring diamonds, and any gem over three or four carats in this hue is an exciting find. Unlike other colours, green is caused by natural irradiation in the earth, probably after the stone's formation. According to Ian Balfour in his book 'Famous Diamonds':
    'The green colour is usually caused by the crystal's coming in contact with a radioactive source at some moment during its lifetime and in geological terms, this is measured in millions of years. The most common form of irradiation encountered by diamonds is by the alpha particles which are present in the magma or kimberlite in minute quantities.' Furthermore, the 'intense green' grade given to this diamond is an extremely sought-after title, as is the extraordinary evenness of colour saturation throughout the diamond. More often that not, any hint of green in a diamond is affected by an outer green 'skin' on the stone, which rarely permeates the full crystal, giving such a beautifully even and true colour, as is the case here.