This process, which dissolves trace elements already present in the sapphire, is completely stable. There is no price difference between heated and non-heated material except for at the very top of the market, where the country of origin will also make a difference in the price. About 90 percent of the sapphire on the market today has been heated to make sure it has reached the best possible color and clarity. As a point of interesting information, sapphire, ruby, and diamond are the only stones that can safely be left in a piece of jewelry when doing repairs. All other stones should be removed and reset after the work is done.
Sapphire is perhaps the toughest and most durable gemstone available on the market.
With a hardness of 9 on the Mohs scale, sapphire is harder than any other gem but diamond and it has no cleavage plane so it cannot be cut with a single blow like a diamond. In fact, synthetic sapphire is used for scratch-resistant watch crystals, optical scanners, and other instruments because its durability can be trusted. That durability ensures that sapphire jewelry will be treasured for generations.