A Star Sapphire is a Sapphire that has a pattern within the stone that emits a star-like effect known as asterism.
A skilled cutter will be able to determine from the rough if a Sapphire is likely to possess the star effect, which is not visible to the naked eye before cutting. The value of the gem will always depend upon how close the star is to the centre of the gem, its clarity, and the depth of colour of the Sapphire. Most stars witnessed on the surface of Sapphires have four prongs; however, in the rarest of cases a six-prong star can be seen, making the gemstone a truly collectable item.
You will find that a Star Sapphire is always cabochon cut, with its dome allowing the asterism to shine through; if it were cut in any other shape the star would be lost.
