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Sapphire , ruby as is known chemically as mineral corundum family , having a hexagonal crystal structure composed of aluminum oxide. As hardness , sapphire has hardness 9 on the Mohs scale , being the hardest mineral after diamond with ruby . It is considered very durable and is ideal for bijuteriiSafirele natural stone extracted from many areas of the globe , but the rarest come from Kashmir and Myanmar ( Burma) , the most precious because their blue color of the nearest spectral blue . Sapphires are found in particular Sri Lanka , but in limited quantities , in both forms , blue and fancy color . Other sapphires are found in Thailand , Cambodia , Tanzania , Madagascar, Australia and even in the USA , in the state of Montana . Natural Sapphire perfect in color or appearance , are very rare and very expensive. By incazlirea controlled sapphires can enhance or diminish their color or improve their clarity . This process produces much better quality stones , the process is stable and lasting , but in such cases jewelers must mention in this market certificates of improving qualities . It is considered the largest and most versatile family of gems stone . Although not shine sapphire diamond , it has a special stralcire . The sapphire is cut in nearly all the cut and diamond. In addition, as ruby , sapphire optical effects can have six-pointed star buy blue sapphire( asterism effect ) , or cat eyes ( chatoianta ) when cut in cabochon shape (also called dome ) . Another unique quality of some sapphires , rubies as to some , is to change color depending on the angle in which the light falls and is viewed from the midline of the stone (this effect is called Pleochroism ) . 38660
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