Talk of sapphires usually brings to mind the intense velvety blues of stones from Kashmir or the cornflower blues of those from Ceylon. However, sapphire is a broader term referring to the gem variety of the mineral corundum that also occurs in a vast range of natural ‘fancy’ colours including green, yellow, purple, pink, orange and black.
No matter the colour the physical properties of a sapphire remains the same, the most notable being their hardness (a 9 on the Mohs Scale, just below diamonds). This hardness makes the stones both durable and lustrous – a gem with good hardness appears more attractive due to the return of light from the surface of the stone.
Yellow sapphires have been gaining interest and popularity on the market; retail jewellers ascribe the increase in value to the rise in popularity of yellow diamonds. Yellow sapphires occur in various intensities and shades, from pale yellow to bright canary and intense orangish yellow. Canary yellow sapphires may lead the Western market, however, further east in Asia there is more interest in deep orangish tones.
Colour variations in yellow sapphires can be the result of several factors: iron levels, natural irradiation, and heat treatment. A fascinating subject under constant research by gemmologists, a recent study determining there are seven types of yellow sapphires, classified by their cause of colour and the stability of that colour to light.
Yellow sapphires are currently being discovered in a variety of localities including Sri Lanka, India and Australia. The beautiful emerald cut, light yellow example illustrated here, originates from Sri Lanka and is just one of a selection of sapphires to be offered in our forthcoming Select Jewellery & Watches auction in London on 21 November 2019.
AUCTION | Select Jewellery & Watches | Thursday 21st November at 2pm | Grosvenor House Hotel, London, W1K 7TN
VIEWING | Thurs 14 Nov & Fri 15 Nov: 10.30-5pm | Sat 16 Nov: 12 noon-4pm | Mon 18 to Wed 20 Nov: 10.30-5pm | 22 Connaught Street, London W2 2AF | Day of sale at Grosvenor House Hotel from 11am