When caring for your jewelry, never use anything but 100% cotton as a polishing cloth since paper, polyester, and coarse fabrics often contain wood fibers or synthetics. These materials may impart fine scratches in the metal, especially on sterling silver. 

A polished appearance is the result of the metalsmith's effort to file, sand and buff the metal to a perfectly flat surface.  When even minor scratches occur, as seen under a microscope, the surface looks like the ragged edge of a saw blade and light is bounced in and around those scratches like a voice echoing in the Alps.  An unmarred surface allows the light to be bounced back smoothly, with no echoes, and results in a highly reflective surface.