TURQUOISE is a brilliantly sky-blue gem, non-transparent, and has been found in tombs of Ancient Egypt, as old as 3000 B.C. In the Ancient Persian Kingdom, the turquoise was worn in necklaces or in rings, to warn of unnatural death. If the colour of the stone suddenly changed, it meant immediate danger for the wearer. It has now been discovered that the stone can, indeed change its colour, but this is because of things like cosmetics, light change and even the ph-value of ones skin, as these things cause a chemical reaction in the gem. But the finest turquoise should have a clear, sky-blue, without dark streaks. Turquoise can be found in USA, Israel, Afghanistan and China.
The most beautiful blue, however, are found in northern Iran.