The CZ stud is 4.5mm and the three CZs in the drop are 4mm. The triple CZ drop earrings measure approximately 14mm x 15mm. This beautiful front-back earring is offered in three finishes. Choose14 karat gold plated sterling silver, Rhodium (a silver white metal that does not discolor or tarnish & is scratch-resistant), or 14 karat rose gold ( 14 K rose gold is a gold and copper alloy containing 58% gold that yields a beautiful pinkish gold color). All finishes are alloys plated over .925 Sterling Silver. Photos of jewelry are enlarged to show detail.