September rolls around and here's the birthstone of the month - sapphire! A member of the mineral family corundum, it's the counterpart of July's birthstone, the ruby. Though sapphire is most associated with the colour blue, it actually comes in every colour of the rainbow - from yellow to pink (is it a ruby, though?), green to orange, violet to colourless.
The most valued sapphire comes from the now-closed Kashmir mines. Today, sapphires are mined in Sri Lanka, Madagascar, Australia, and some parts of Africa and America.
Of these locations, Sri Lanka is one of the most prolific producers of fine sapphires. The Sri Lankan government's efforts to minimise large-scale mechanised mining seems to be working very well, as they keep mine ownership mainly to the locals. As a result, the gems come out of the ground slowly but steadily.
With sapphires as good as these, the supply won't be able to keep up with the demand, ensuring ever-increasing prices, which is good for the economy over there.
Ceylon (the old name of Sri Lanka) sapphires are known for their depth of colour and low number of inclusions. Of course, they don't all start that way - many of them start as rather cloudy, light blue stones, known as geuda.
To get to the colours that are in demand, most of the sapphires from the mines are heated. Chemical treatments are sometimes used, which further lower the value of the stones, but they are used only on the poorer quality ones, which would be hard to sell anyway.
At the top end of the market are the high-quality unheated sapphires that are of good colour. Needless to say, these are very pricey, but still much sought-after, especially by the connoisseurs and the wealthy.
Sapphires are one of my favourite gemstones. I can never get enough of that rich, lustrous blue. Share your thoughts on sapphire with us! We'd love to hear from you.