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Any gem quality stone within the corundum family is generally called sapphire. The exception to this are red stones which are of course known as rubies and pink or orange stones that are known as padparadschas. They share many of the same characteristics as diamonds althought are not as hard and durable. In fact, corundum is so hard it is often used in industry for abrasive and cutting purposes, like emery paper and drills. Rubies and sapphires are also used in lasers: in 1960 the first laser was invented and a ruby was used to create the laser beam which was a red colour as seen in James Bond!
Sapphires are mostly found in Sri Lanka, formerly known as Ceylon and these are a lovely cornflower blue shade although they also come from places such as Madagascar, Burma, Thailand and Tanzania.
Despite the fact that people generally think of blue sapphires in engagement or wedding rings, there is a wide range of types and colours, but they also share the same refractive index so can be identified easily by a gemologist. The blue shade is the most popular for wedding rings however at Harriet Kelsall Jewellery Design we use sapphires of differing shades all the time. If a sapphire is to be called blue it must not have more than 15% secondary colour tones (eg. yellow or pink) within its structure. Any more than this and it becomes something along the lines of “greenish-blue” or “violet” which are then called “fancy colours”.
Although deep colour saturation within a sapphire is normally regarded as good because it gives a fine, deep colour (and therefore makes it more expensive) there is such a thing as too much of a good thing. The blue colour comes from titanium, and too much of this in a stone makes it look almost black, which reduces its value as the overly dark effect is not generally desirable.
At the other end of the scale, clear, white sapphires are the purest form of corundum because they contain none of the trace elements which cause colouration. They can be used as an alternive to diamond for your wedding ring. Having said that, large stones are not that widely available because it’s not easy to find that purity in nature. Stones with colourless areas are more common, and these are generally cut so that the colour is at the base. This means that when it’s viewed from above, colour fills the stone.
Pink sapphires have become more widely available since the 1990s when new sources were found in Madagascar. Until then, they were exceptionally rare, and found only occasionally in Vietnam, Sri Lanka or Burma. Because of the new availability, their popularity has shot up in jewellery and especially wedding and engagement rings. They come in a full colour range of the palest pink through to fuscia, and all colours seem to be equally popular. The colour comes from traces of chromium.
Naturally occuring orange sapphires are exceptionally rare, however heat treated stones are available.
Yellow sapphires also come in a wide range of colours and tones from light canary through to a deep golden. Until the end of the century, it was not known that sapphires were anything other than blue. As a result, they were known as ‘oriental topaz’ up until that point.
Green sapphires vary between light lime green and olive in colour. Many actually consist of very fine bands of blue and yellow, which can be seen under a microscope, but blend if looked at with the naked eye. This was once known as oriental peridot.
Lavender and violet colours of sapphire are quite rare, and often reminiscent of tanzanite although more durable. They can be quite expensive in larger sizes if they are of a good quality.
Star sapphires and rubies are classified a “phenomenon” stone. They are likely to have contributed to the legend and lore concerning the powers of the sapphire because the very first sapphires cut would have been shaped in a cabochon form and when the stars appeared no one could explain them! We now know that star sapphires have to be cabochon cut to allow the 6 pointed star to be created within the sapphire, which happens because of the way a single point of light reflects from the internal structure of the stone. The correct angle of light entering the stone bounces off the needles and accentuates the appearance of the star. They come in a wide variety of colours, although the most prevalent are a greyish white or greyish blue.
Its a shame that for such a fabulous stone, most rough star sapphires are put into high temperature ovens to melt the silk-like needles and destroy the star effect. This is simply because they are worth more as classically facetted sapphires. Heat treated star sapphires do exist but are hard to make because the intense heat needed in this process damages the needles that produce the star.
Colour changing sapphires are also classified a “phenomenon” stone. Many people do not believe they exist until they see them in real life. Generally, in fluorescent lighting these stones look blue and in incandescent light they look purple, although they also come in a colour change of red/brown, green/red, and green/yellowy green. A ring with one of these stones set in it can look like two different rings depending upon the source of light! A stone with a complete colour change (eg red/green) is more expensive than one with a more subtle change.
Padparadscha is the only variety of corundum other than ruby that is not simply known as a colour of sapphire. Its name is an ancient Sanskrit word which describes the colour of the lotus flower – a pinky orange colour. Padparadscha is extremely rare, and as such, very expensive, particularly for a fine piece. Similarly coloured stones are not classified Padparadschas if they have any hint of reddish orange or brown in them, although these too are stunning stones.
Sapphires are the birthstone of September and the astrological stone of Leo. The various colours are thought to protect the wearer from all sorts of evil, illness, stress and general harm, and as such, a wonderful choice for your wedding ring!
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