I’ve tested thousands of pieces of jewelry over the years to see if they contained precious metals or not. One thing I’ve learned from testing silver jewelry is that quite a bit of it can be sorted and eliminated without using test acids.
The two methods described here work best when:
You have a piece of jewelry that looks like silver but is not marked
You have a marked piece of silver jewelry but are not sure if it’s real
You have a lot of jewelry items to sort through, and want to quickly remove everything that is not real silver
Use a Magnet
The first method is easy but it will eliminate a ton of silver-colored jewelry that would otherwise require an acid-test to see if it is real silver or not.
In fact, the hardest part about this method is probably finding a suitable magnet. Ideally, you want to use a rare earth magnet because they’re extremely powerful in a very compact size. These can be found on Amazon and eBay, or at your local hardware store in some Magnetic Pickup Tools (Collapsible wands, pens, etc).
Once you’ve got a good, powerful magnet, simply place each piece of jewelry by itself on a flat surface then slowly move the magnet closer to the jewelry and observe any reaction. Iron-based items will literally JUMP onto the magnet, the attraction is so strong. Some other items, the attraction is not as apparent, which is why having a strong rare earth magnet is important.
With necklaces and bracelets, it may be easier to dangle the piece of jewelry in the air with one hand while moving the magnet with the other.
The magnet won’t tell you what IS silver (or gold), but it will tell you WHAT IS NOT. If it sticks to a magnet, it is not made out of precious metals.
Use a Test Stone
This is a just a small, unglazed tile that provides a rough enough surface to remove small bits of metal that are rubbed against it, and also a resistant enough surface that the metal bits can be tested for precious metal content by placing drops of nitric acid on it.
But you don’t have to use test acids to get value from a test stone. Simply rubbing a piece of jewelry back and forth across the stone’s surface a few times is enough to remove some metal from the jewelry and get down to the base metal on most plated items. This is extremely handy for pre-testing silver-colored jewelry that isn’t marked.
Why? Because quite a bit of silver-colored jewelry is plated, and the base-metal underneath the plating is a completely different color (usually copper). By rubbing the jewelry in question on a test stone, you’ll often see a copper-colored line appear on the stone, instead of the expected silver color. This is a fast and easy test to eliminate the majority of silver-plated items.
Test stones can be found on Amazon or eBay, sold individually in various sizes or included in gold testing acid kits. Some of the local hardware stores and hobby shops have also started selling test stones for a couple bucks or less but most any unglazed tile will work.