These earrings set with very distinctively cut rock crystal are known as Stuart crystal, which was originally worn by loyalists to the Stuart monarchy after the execution of King Charles in 1649. The first Stuart crystal jewelry featured either the likeness of the martyred king, a lock of his hair (for the lucky few), or a cipher of his initials under faceted rock crystal (hence "Stuart crystal"). Later pieces feature a foiled back and/or a background of hair, sometimes with initials belonging to the owner or a loved one, but always with the style of crystal seen in these here. These lovely earrings converted from cuff links were made toward the end of the 17th century. Each crystal is set in silver and encases a lock of hair.