Star sapphires are one of the 'phenomenal' gems displaying various forms of light. The star is formed by needles of rutile within the sapphire which are aligned at 120 degrees to each other. It is important to have a clearly defined, central star with equal length arms. As you see, this is a fine example, probably from Sri Lanka, with a lively sapphire, evenly coloured, and a delicate shade of dove-grey. The calculated weight of the sapphire is just over 20 carats, and the platinum mount is set with small circular diamonds, with five marquise-cut diamonds on each shoulder, with a total of approximately 1 carat. It is a substantial looking ring - the head is approximately 20 x 20mm overall