Srilanka, June 22 -- A stunning gold ring lost at a medieval castle in Slovakia over 700 years ago has been found to contain a Sri Lankan reddish-purple sapphire set in a band flanked by lions.

Noemi Beljak Pazinova, an archaeologist at Constantine the Philosopher University in Nitra, is researching the provenance of the ring, which was discovered at the Zvolen Castle in central Slovakia. Although rings were common accessories for men and women in medieval Europe, the discovery of a gold ring with a valuable gemstone is extremely unusual, the researchers wrote in the study published by the Journal of Archaeological Science.

They determined that the band was made from 18-karat gold and that the gem is a two-carat corundum, a hard minera...