This ring is decorated with a Renaissance quatrefoil or four-petalled bezel finely decorated with black and white enamel. 'Blackwork' enamel first appeared around 1585 and remained in fashion until the 1620s. It consisted of patterns of small curved and broken scrolls against a black or white enamel ground, contrasting with the bright enamels popular earlier in the sixteenth century.
It is set with a pink sapphire. Sapphires and rubies are both varieties of the gem mineral corundum. The rich red colour of rubies is created by the presence of chromium whilst sapphires may be found in a range of colours from colourless natural corundum to yellows, pinks, greens and the most highly prized blues. The term ruby was used in this period to describe a number of red stones including garnets, spinels and pink sapphires. It is possible that the original owner of this ring believed the stone to be the highly prized ruby, a stone valued for its rarity, beauty and talismanic or magical qualities. The sixteenth century owner may have believed that a ruby would protect him or her from perils, including the loss of land and rank, as well as demonstrating his or her status and good taste.