Reputable and trustworthy come to mind when speaking about a jewelry company in business in San Mateo since 1937. Steiner's is offering its high-quality diamonds, colored gemstones and watches in a new upscale store. Its trademark is combining classic designs and valuable precious stones to create heirloom pieces for generations to come. Resizing, as well as buying or trading old or broken gold, platinum and gemstone jewelry is available.