Solder (also spelled soder by some) is a metallic compound that when heated, and subsequently cooled, fuses 2 pieces of metal together. Generally solder is silver in tone, but not always made of actual silver. Ok, anywho: older tea sets are made of pure silver. The solder they used to fuse the handles of cups, or the spout of the tea pot to the base is actually silver solder, made from silver, not just silver colored.