#1. Rub the jewelry using a soft white cloth. If you find any back marks on the cloth, then you can be sure that it is made of real sterling silver. This is because any air exposure causes real sterling silver to oxidize. This causes them to deteriorate with time, and the reason why black marks are found on the cloth they are polished with.
#2. Do The Nitric Acid Test. When drops of nitric acid are added to fake non-silver jewelries, they cause them to lose their color. Always ask a jeweler before buying 925 sterling silver from him if you can conduct the nitric acid test on it.
Nitric acid has no effect on real s925 sterling silver, so if the jeweler is selling you a genuine product, he won’t have any objection to that. But be sure to wear gloves and protect your eyes with goggles while doing the nitric acid test.
If the jewelry is made of real sterling silver, the part on which you drop the nitric acid will appear creamy in color, otherwise, if fake, it will appear green.
#3. Use the Smell Test. Real sterling silver shouldn’t smell. If it does, it is because there is too much copper in it.
#4. Use the Magnet Test. This is a simple test. Magnets have no effect on silver – just as they have no effect on gold or platinum. But if you find that the jewelry is attracted to the magnet, then it will be clear to you that it is not made of real sterling silver.