Platinum and sterling silver both look similar, and that makes it important to know how to tell these two metals apart. They are both used in numerous types of jewelry products with sterling silver, which can be found in almost any large department store. Most wedding rings are made out of platinum as it is stronger, whereas silver is a softer metal that gets dirty easier and is not meant to be worn every day. Many of the smallest jewelry items will feature a platinum component as opposed to the larger pieces due to the price of platinum on the open market. Silver is often mixed with another metal such as copper in order to increase its strength and this is where the phrase silver-plated comes into play.
Look at the price of the items as this is usually a quick way to tell the two apart since sterling silver will always be cheaper than platinum. It takes much less work to extract silver out of the ground and so it is not as rare as the other metal. Another giveaway is the actual size of the jewelry since you will only find platinum in the smallest designs such as wedding bands, earrings or necklaces due to its price. If it is a larger product then it is very likely that it has been manufactured using sterling silver.
Examine the color of the two metals and notice which one looks a bit whiter in appearance. Platinum looks almost white, whereas silver has a more grayish tint to it and is also prone to oxidation which may cause it to start turning black.
Bite down on the jewelry piece and see which one feels tougher, as you probably have seen done in movies numerous times. This might not be appropriate at a jewelry store but is one way to check which is which. Platinum is much denser than pure sterling silver and this can be felt when biting down. Although you will not be able to bite through either of them, and this is not the point, you will detect the denser of the two.
Place the jewelry pieces of a similar shape and size on a digital scale, one at a time. Weigh them and notice which one is heavier. This will be the platinum piece.
The black tarnish on silver caused by oxidation can be removed by rubbing it with a sodium bicarbonate paste or it can also be cleaned by a professional jeweler.