September's birthstone: Sapphire - the medieval super-stone

By Chloe Tomasik - 12/09/2007

 Sapphire is September’s birthstone and 'super-stone' of the medieval period. It kept the clergy clean, the apothecaries in business, the assassinations at bay, and was the must-have item on all good witches’ wish lists.

The history of sapphires well documented. They are mentioned several times in the bible - one was in Aaron’s breastplate and tradition has it that the law given to Moses was written on a tablet of sapphire. However, doubts have been raised as to whether this was actually sapphire or lapis lazuli, as in ancient times all blue stones were labelled sapphire. From as early as the 2nd century Damigeron wrote that "a sapphire worn around the neck of a King would protect him from attack and being poisoned." However, only certain stones were able to detect poisoning. To test the suitability of a stone, a spider was put in a vessel and a sapphire swung above it. If the spider died, the stone was considered "fit for purpose."

As the centuries went by quite detailed descriptions were given of how sapphires could cure illness. They could be ground into paste to cure ulcers and stomach cramps or rubbed on wounds to aid healing. In 1650 one apothecary recommended rubbing a sapphire of ‘deep colour gently’ around a boil. Relief wouldn’t come immediately, but given time - and presumably luck! - the patient would eventually feel a lot better. The theory was that a magnetic force existed within the stone which would draw out the pestilence and poison from the infected part. And of course boils were particularly common at this time due to the plague. To further increase effectiveness, it was even suggested that the sapphire be engraved with the figure of a ram or a bearded man.

Many religions appeared to appreciate sapphires. In the 12th Century Pope Innocent III decreed that all Bishops wear sapphires, as they were thought to "check the ardour of lust, make a person chaste and virtuous- and restrain too much sweat." Hence, rings of office of the higher clergy were set with sapphires to ensure purity of thought and deed. The Hindus thought the blue sapphires conferred happiness, wealth and the favour of Princes. The Buddhists had less materialistic views, believing that sapphires encouraged prayer, gave peace of mind, tranquillity and spiritual enlightenment. And, just to complete the picture, necromancers and witches also placed great value on sapphires, as wearing one would enable the former to interpret their predictions more easily and the latter to "fix" their spells!

Sapphires have always been very popular and, because they have been found in large crystals, some stupendous gems have been sold to royalty and film stars alike, particularly early film stars. Joan Crawford had a great penchant for sapphires - so much so that a particular blue of sapphire became called Joan Blue. Her engagement ring was a 70 carat sapphire. Jean Harlow, another film star with a fondness for sapphires, had an engagement ring with a whopping 150 carat sapphire. She wore it in her last film, Saratoga, in 1937. These make the late Princess of Wales’ 18carat sapphire and diamond engagement ring seem modest in comparison.

The name sapphire comes from the Latin Sapphirus, meaning blue. However, sapphires can be any colour but red. They are from the corundum family - the same as a ruby. However, only a red stone can be called a ruby. Generally all colours other than blue are called ‘fancy sapphires.’ The different colours are determined by the impurities in the stones. Pus iron gives a yellow or green sapphire, a tiny amount of chromium can give a pink colouring whilst a purple sapphire will have traces of vanadium. Corundum itself is white and this is often heat treated to give another colour. Today 90% of modern sapphires are heated to improve their colouring.

In the past Ceylon and India were the areas that produced the best sapphires. Today sapphires are mined all over the world from the unlikely sounding Yogo mines in Montana to Australia, Thailand, Brazil and Africa. The different areas will mine different shades of blue sapphire due to the trace minerals of the area. Montana sapphires are quite dark and have an almost metallic sheen. Kashmir sapphires are considered the best, producing the highly prized cornflower blue stones, whilst Australian sapphires tend to be much darker in colour and consequently less valuable.

Sapphires are 9 on the scale of hardness, just below diamond. It is because they are so hard they are often used as the crystal (i.e. ‘glass’ cover) on some Rolex watches to prevent the face getting scratched easily. They are also found set in the winder of high end ladies watches (for style), such as Cartier Tank watches. Even the mundane emery paper found in many a tool box is a form of corundum.

On a practical level sapphires, being such a hard stone, will not scratch easily and can be cleaned by brushing with a soft toothbrush in a very dilute ammonia solution or given to a jeweller with ultra sonic cleaning equipment to help keep your sapphires "the jewel of jewels."