To the average eye, it may seem difficult to distinguish whether a certain metal object is pewter or silver, especially if the metal item in question is an aged antique that has seen its fair share of wear. Pewter, for example, was used in many antiques -- especially British ones -- because of how soft the metal was and how easy it was to melt it down and recast into different shapes. Multiple ways can be used to tell the difference between silver and pewter.
Tarnishing can distinguish whether your item is silver or pewter because silver tarnishes while pewter does not. If you have, for example, a candelabra and are unsure of what metal it's made from, examine whether or not it tarnishes after being left out for a period of time. If tarnish begins to show, your item is silver.
Look for specific markings, especially if your item in question is a piece of jewellery. Usually, real silver will be marked with ".925," which means it is sterling silver. If it marked with an "800" or "900," your silver is a blend of different metals in which real silver may or may not be present. Also, look at surface markings on your item. If it is very smooth, most likely it is silver. Pock marks and other small indentations mean it is pewter, since the metal dents easily.
Examine the colouring of your item. Silver is usually shiny and "silvery," after its name. It's a bright metal with a high lustre. Pewter, on the other hand, looks more like lead and has a much darker, duller sheen than silver.
Use a nitric acid test to determine whether the metal is silver or pewter. Nitric acid tests are inexpensive and can either be ordered online or bought at a jewellery supply store. Once you have your test kit, make sure you are in a well-ventilated area and carefully apply a drop of the nitric acid to a cleaned portion of your metal. If the acid changes colour, it means your item is silver.