Star rubies are a rare variety of the gemstone ruby. These magnificent gems display a sharp six-rayed star which seems to glide magically across the surface of the gem when the latter is moved. This is caused due to an optical phenomenon known as Asterism. The star is best visible when the star ruby is seen in a single light source such as sunlight and spotlight. Star-effect or Asterism is caused by the dense inclusions of tiny fibers of rutile (also known as Silk). The stars are caused by the light reflecting from needle-like inclusions of rutile aligned perpendicular to the rays of the star. However, since rutile is always present in star rubies, they are never completely transparent. In fact, star ruby is one of those few gemstones which actually require inclusions (I.E. Rutile). Most rough rubies that can be cut into stars are mined from burma (myanmar), srilanka, india, africa, vietnam, thailand, afghanistan, pakistan, australia, cambodia, united states. The most commonly available star rubies are usually from africa and indian. Star rubyis a rare variety of ruby that exhibits asterism a six-rayed star that shimmers over the surface of the stone when it is moved. The star effect is owed to aligned needle-like rutile inclusions. It is the rutile which is responsible for its silky shine. In rough form,rubyis dull and greasy, but when cut and polished its luster is comparable to fine diamond. Ruby is classified as the red form of gem-qualitycorundum all other color varieties of corundum are referred to as sapphire. Corundum is the second hardest mineral on themohs scale, with a hardness rating of nine. Owing to its superior hardness combined with its rich color and silky shine, fine quality ruby is classed as one of the group of four so-called Precious stones, along withdiamond,emeraldandsapphire. Ruby gets its name from the latin word ruber, which means red.