Oxidized sterling silver
During the oxidation silver becomes matte dark. This is a short-term effect that gradually wears off making the jewelry appear antique. The finish can be re-blackened easily with silver oxidation solution, available at most jewelry suppliers
Brushed sterling silver is opaque. Over time the texture gets polished naturally and becomes increasingly glossier.
The surface of polished metal is glossy. If looked after the changes to the texture should only be minor.