Yvonne Bolger Earring Collection Sterling Silver Stud Earrings Shaped Like Sea Shells. Capture the feeling of wind in your hair and the smell of the Ocean wearing these Art Deco inspired Dainty Stud Earrings. Shell is 4mm Long and 4mm Wide approx. Stud earrings with a Butterfly/Push back on Post. Very slight variations may arise due to the hand crafting of each individual piece. All pieces are Hallmarked by the Irish Assay Office.