Our newsletters on gemstones continue, and this week we’ll focus on the blue sapphire.
Sapphires come in all colours and rubies are a part of the same group, which are called corundum. Nevertheless, the blue sapphire is something notably special.
Sapphires are found mostly in Australia, Thailand, Madagascar, and Sri Lanka. There have even been found blue sapphires in Montana but with a greenish overshine and have therefore been coined fancy names like ‘wintergreen.’
Yet the finest of all sapphires are commonly from Kashmir, but why is it that we love Kashmir sapphires so much? These sapphires tend to have a sleepy quality which is quite difficult to describe. It is the result of a myriad of tiny inclusions, sugar-like grains, which are difficult to resolve under the highest magnification. Yet the small inclusions give the stone an overall sleepy or velvety appearance. No more sapphires are mined from Kashmir, and the last extraction occurred over 100 years ago.
Closely following the quality of the Kashmir sapphires, are those from Sri Lanka. These sapphires have a better crystal structure and as a result, they seem to be brighter in colour. As always, you are the best judge, which colour do you prefer?
What colour are we looking for in blue sapphires? We look towards the primary colour, and we want to find a deep vivid blue or a vivid purplish-blue. Not too dark, and not too light. This is commonly described as ‘royal blue’ and is the colour you can find in the engagement ring of crown princess Kate of England (previously the ring of princess Diana). In short, the colour of the blue sapphire should be very blue, and the more velvety it looks, the greater the value.
Possibly to your surprise, almost all blue sapphires have been heat-treated. Some stones lighter in colour from Sri Lanka are unheated, yet most of the finer stones we see on the market are heat enhanced. The process involved ‘cooking’ the stones for several hours at a certain temperature, which results in a chemical structural change, and sometimes the colour will enhance. Yet heating has an overall negative effect on the blue sapphire and often heat-treated blue sapphires have a poorer crystal than unheated stones. Additionally, the heating processes can also reduce the transparency or even muddy the crystal. If all other factors are equal, then the very best natural coloured sapphire will be more beautiful than the very best heat-treated sapphire.
For some, the blue sapphire will bring fortune beyond measure, good health, and a lifetime of prosperity. Yet for others, the stone will immediately cast darkness and chaos. The only way to know its effects on you is to test the stone. You should spend a few nights with the blue sapphire under your pillow to know what exactly the sapphire will bring to you.