1.65 Demantoid Garnet Engagement Ring in 14K Yellow Gold1. 65 Demantoid Garnet Engagement Ring in 14K Yellow Gold. This modern engagement ring features a 1. 65 carat natural demantoid garnet and . 27 carat accent diamonds in 14k yellow gold. As one of the rarest garnets, this light yellow green hued gem is oval cut and set in four prongs. Eighteen (18) . 015 carat natural diamonds are mounted on both sides of the primary stone. From the profile, the solitaire demantoid garnet is elevated slightly above the