Dainty Montana Blue Stud. The Montana Blue Pierced Earring Stud:This Montana Blue Mini crystal Pierced Earrings Stud is Unique and effortless in design. These crystal Pierced Earrings highlight bezel-set crystal. Approximate diameter: 1/8 inch, length 1/2 inch. In simple design, these stud earrings are practical day wear and will also make a big impact when the occasion calls for a celebration or time out on the beach. Blue, crystal, Stud, Butterfly, Copper, Not Handmade, Polished.