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, like these earrings, feature a pink foiled back and/or a background of hair with initials belonging to the owner.