Christie’s The New York Sale scheduled for April 16, will also put on offer a diamond reputed as the most chemically pure type of diamond with exceptional optical transparency. The diamond is a rare cushion-cut stone of 39.34 carats, graded D color, with internal flawless clarity and designated as Type IIa. It maintains perfect symmetry and cut. The diamond is estimated to be worth $6-8 million. %% Type IIa diamonds are exceptional family of gems which do not carry traces of the colorant nitrogen. The absence of this element, seen in 98% of diamonds, gives the stone a purity of colour and degree of transparency carried by only the very fine diamonds. In addition to its colour, clarity and brilliance, the cut of this stone is paramount and has achieved an excellent rating for polish and symmetry, allowing it to perfectly balance on its culet. %% The gemstone embodies limpid transparency, extreme brilliance and a sophistication replicated like the finest diamonds found in the mines of Golconda in India, or in Brazil or South Africa. The cut and soft shape of the diamond is similar to the Polar Star diamond renowned for its unsurpassed brilliance and precision cut. The Type IIa diamond, at the auction, will bring in the allure of the rarest diamonds.