Sapphire occurs in a wide range of colors such as blue, pink, padparadscha
orange, yellow, green, purple, black. Color is due to trace impurities of Fe2+, Fe3+, Ti, and
yellow color centers. The most expensive color is an intense cornflower blue; these are sometimes referred to as "Kashmir" sapphires having a highly saturated, slightly milky, violet
blue color. Padparadscha is next in value, followed by pink, then orange, purple and yellow,
respectively. Nowadays 400–500 tonnes of synthetic sapphire are produced by the Verneuil
process each year.
In jewelry, as phonograph needles, industrial abrasive, watch and instrument bearings.