Instruction
Take the stone to clean your hands or with tweezers and carefully inspect it under bright natural light. You should see the inside of the shining hexagon, which is created by inclusions of rutile in the stone. It is for this sparkling six-pointed star inside the sapphire, and is prized among the other stones.
Prepare a solution of water and glycerol, dip it. A real sapphire would not be visible in this solution, fake you will see without much difficulty.

If you submerge the stone in gemology liquid with a certain specific weight, the heavier the sapphire will go to the bottom, unlike imitations of his lungs. Disguised as sapphire are usually painted glass and plastic, tourmaline and other stones. In addition, the fake color in the edges will be unevenly distributed, and the sapphire in his careful examination you will see a clear strip that is located parallel to its faces.
Take ruby or emerald and then drag them across the surface of the intended testing of sapphire. If the sapphire stone is natural, strips and damages should not stay. Just not worth it to do podophyllaceae diamond, as it can leave a scratch on the sapphire surface (diamond is the hardest of minerals, and they cut things and much sturdier sapphire). The method is quite extreme, but if you have nothing to lose - experiment.
Seek the expertise of a specialist-gemmology in that case, if you still doubt the authenticity of the stone and are afraid to conduct their own experiments with it to research its authenticity, which is not surprising, because you can damage your expensive stone. But be prepared for the fact that even a skilled professional can always identify a well made forgery.
Ask the seller when buying a gemstone certificate to them, certifying the authenticity of the stone, and at refusal of the seller to provide a certificate, or, failing that, give up the purchase of this stone, as if beautiful and attractive it would you may seem - it is possible that you will pay a lot of money for painted glass. Guided by the reputation (it has to be immaculate) salon or store when you purchase a sapphire in the finished product.