Tourmaline is one of the traditional birthstones for the month of October,People can call Tourmaline for gemstone.
ourmaline is a complex boron silicate mineral, the colours they come in are as a result of additional elements being compounded with it when the stone is forming. These elements include aluminium, iron, magnesium, sodium, lithium and potassium.
The name Tourmaline comes from the Sinhalese (Sri Lankan) word turmali which depending on the source means either "stone of many colours" or "stone attracting ash".
Tourmaline has a hardness of 7 - 7.5 on the Mohs hardness scale which makes it a very suitable stone to use in many types of jewellery.
From ancient times Tourmaline has been referred to as the rainbow stone. There is an old Egyptian legend that tells of how the stones travelled out from the core of the earth on a rainbow and as they slowly made their way through the earth to the surface they were coloured by the different hues of the rainbow resulting in the myriad of amazing colours we now see in the Tourmaline spectrum. Other ancient civilizations believed that Tourmaline had mystical powers that could help in protecting them from different types of danger and misfortune.
Tourmaline exhibits quite a remarkable magnetic tendency, especially in the opaque Black Schorl and Yellow Tsilaisite varieties. This occurrence is due to the higher levels of iron and manganese contained within the gemstones themselves. The stones have both positive and negative sides just like a magnet. The magnetism is more apparent when the stones are warm and they will attract more dust and other particles when in this state. The Dutch used to use the magnetic properties of Tourmaline to pull ash out of their tobacco pipes hence it being referred to as "stone attracting ash".
Tourmaline is sometimes heat treated or irradiated to improve its colour. Many varieties of gemstones are subjected to this type of treatment. With Tourmaline these treatments are mainly done to lighten or even remove all of the colour from the stone. By subjecting deep red stones to temperatures of up to 520 o celsius over many hours various shades of pink can be achieved.
This is not such a common occurrence though as there are already over 100 different varieties of Tourmaline that are known.
Some of the more well known Tourmaline gemstones include: