Small nicks and scratches in decorative iron pieces can be covered with black crayon. Wipe off the excess with paper.
To remove ink prices from matte-finished pottery, try paste silver polish. It is a little abrasive and contains some cleaning chemicals that may help.
If you are having antique jewelry repaired, be sure the jeweler uses old stones. New ones are cut differently and will be brighter. Old pearls and turquoise change color.