Star ruby is a phenomenon gemstone. Ruby may display stars. Fine star rubies display sharp six-rayed stars well-centered in the middle of the cabochon and you may see even twelve-rayed stars depends on light sources. All legs of the star should be intact and smooth. Just having a good star does not make a stone valuable. The best pieces have sharp stars against an intense crimson body color. Lesser stones may have sharp stars, but the body color is too light or grayish. Many star rubies are also heated in the presence of a flux to heal their fractures. Untreated stones fetch premium prices.
The star ruby cabochon accented with single and brilliant-cut, baguette and triangular diamond decoration, size 48, numbered ,from Sotheby's auction.
