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Evaluating Sapphires

The most attractive Sapphires are those that are a pure blue. Whilst pure body colours are desirable in most gemstones, those whose colour is a primary colour such as the red of Rubies and the blue of Sapphire, really can demand a price premium when their hue is pure. That said, some gem collectors prefer their Blue Sapphires to have a 10 to 15% purple mix within the gem’s colour.

In terms of saturation you will sometimes see a greyish mask (see mask heading in Volume II to get a better handle on saturation and masks) and if the gem lacks life this could be the cause. In terms of tone it depends on your preference between lighter cornflower blues and deeper royal blues. Unfortunately today we see far too many Sapphires on the market, especially from some locals in China and Australia, where the tone is almost 100% (i.e. black).

Another important evaluation criterion for both members of the corundum family (Sapphire and Ruby) is whether the gem bleeds or not (see bleeding heading). When some Sapphires are worn indoors under incandescent light, they can often lack sparkle, their tone seems to diminish and the gem almost fades, but take them back outside and they instantly revitalise. Not all Sapphires bleed in the same way and the level of their bleeding depends on their chemical composition.

Probably more than any other gem (with the exception maybe of Pearls), Sapphires have often been valued more for their origin than their beauty. But to paraphrase the most legendary of all gem explorers ever, George Kunz, great gemstones can be found in any location and poor ones can be unearthed at locales that are renowned for the most highly prized. You are just as likely to find a poor quality Sapphire in Kashmir as a stunner in China.

The key evaluation criteria for Sapphire, as with all coloured gems, remain the vividness of its colour, its transparency, its clarity, its cut, etc. Then of course, if you are faced with a choice of two similar gemstones from different locales, you might choose to acquire the one with an origin that is renowned for producing great pieces of that gem variety, or you may even choose the other piece that is the shining star of an under-rated locale.

Let’s discuss the properties that are typically associated with each location, but please do bear in mind the above comments. These are the summary of the huge amount of books I have read, yet my own experience is more in line with the views of George Kunz in that quality and appearance can vary from location to location.

My opinion, that it is not wise to generalise about locales, is based primarily on viewing the gems that flow through my sorting office in Jaipur and those that we sell through our various channels. It is also based on the fact that when I was recently in Zambia I witnessed from one small location in a mine, no bigger than three foot square, a miner unearth the most stunning, clear deep green Emerald, only five minutes later to find two more pieces that were dull and lifeless. The difference can be narrowed even further: it’s not just the country, the region, the particular mine, the area within the mine that makes a difference, but the portion of the rough that your gem has been cut from. Only yesterday I was in my cutting facility where we were cutting some of the finest Amethyst rough we have ever purchased: after making the first slice (a slice is the first cut made to gemstone rough, performed to remove a part of a gem with a big fracture or large feather inclusion), we were left with two totally different grades.

So the information below is more related to the typical types of Sapphires found in each location. It’s more like saying you will find more Brits in Britain, more Thais in Thailand and more Indians in India. But if you look in today’s cosmopolitan cities, you will realise this type of view is no longer completely valid. It is also important to point out that with today’s modern gemstone treatments, such as colour diffusion, these differences are less reliable than they used to be in terms of arriving at a dependable origin, based on appearance alone.

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