Matthew Calvin Trim Stud EarringsThe Trim Studs, together with the rest of the studios Machinist collection, were inspired by shapes from architecture and machines. However, the resulting pieces and these beautiful, simple studs retain an identity all of their own. Available in sterling silver and gold plated finishes. Size: 4. 5mm Care All of Matthew Calving jewellery is made in solid Sterling Silver. Silver will eventually lose its lustre or shine. To keep your jewellery looking