When the natural beauty of the gemstone sapphire is enhanced by a white starburst splayed over its surface, the gem is called Blue Star Sapphire. Ranging from cornflower blue to deeper hues of cobalt, sapphire can be clear, translucent, and nearly opaque. All are lovely colors to emphasize the star of white, giving a brilliant watchful look on the gemstone face. Sapphire is a corundum coming in yellow, pink, purple, and green. Nature also offers corundum in red, but then it is called ruby. The opaqueness of a sapphire comes from slender needle-like rutile inclusions. When these inclusions, called silk, are thicker they result in asterism, or star appearance, in either six or 12 rays. These milky white rays add a natural exotic appeal to an already fascinating stone in the gem world.
On the more opaque stones the star rays sometimes appear higher to the surface, while on darker blue, translucent gemstones the white points seem to be deeper set in. Lighter colored stones sometimes also appear to have gray or gunmetal tones. Blue Star Sapphire often displays differing shades of blue as light is reflected at various angles. This deeply colored stone is exceptionally hard, second only to diamond, and has been the choice of royalty and heads of state for centuries. It is usually cut into cabochon shapes and highly polished to promote the star qualities. A Blue Star Sapphire will lose its star if faceted.
Used as September’s birthstone, this gemstone is often set in rings, earrings, and pendants in either silver or gold. Surprisingly, naturally occurring Blue Star Sapphires may have off-center stars and irregular star rays, whereas sapphires with fabricated or artificially induced stars are straighter. This makes the more ‘perfect’ fake stones easier to spot from true Blue Star Sapphires. When choosing, watch for the telltale imperfections of the genuine star.
Compound : Aluminum Oxide
Mohs Scale(Hardness) : 9
Found : Australia, Burma, Cambodia, Madagascar, Sri Lanka, Thailand, Tanzania, and United States