Elain's engagement ring was given to her when Graysen proposed. It is made of iron.
He and his men were in charge of hunting down faeries who ventured south of the Wall. Graysen agreed with his father's opinions of faeries, and therefore decided to propose to Elain with a iron engagement ring with the belief that iron could kill faeries and prevent them from controlling their minds. However, in reality, iron is useless against faeries and provides no protection.
Elain's engagement ring is made of shining iron and decorated with pearls and diamonds.