Hello all, a few posts ago, 
The first thing to do is be sure to purchase your silver from a reputable dealer. I'll recommend:
- http://www.jmbullion.com
- https://www.providentmetals.com
- https://sdbullion.com
- http://www.apmex.com
- https://www.amagimetals.com
I'm sure there are many other great ones. Beware buying from Ebay or some market like that, be sure the seller is highly rated. If the deal is too good to be true, it probably is, test test test!
Once I get my silver (or gold) I do these things:
Step 1: Weigh it
It's good to make sure your silver weighs as much as it is supposed to. You may as well right? It's an easy check and there is no real reason not to do it.
Step 2: Magnet test
Another test I like to do that's pretty easy is the magnet test.
I use a neodymium magnet which are super cheap and easy to come by, and chances are, you may already have one stuck on your refrigerator.
The magnet should not stick to your silver piece. If it does, that means there is something ferrous in it and that would not be good at all. But the magnet should have a small attraction to the silver, and you can see that by letting the magnet slide down the silver when held at a steep angle.
Magnet should slide down slowly..
You can slide the magnet down a control object, like a book held at the same angle, and you'll see it slide down much faster.
Step 3: Sigma Metalytics Precious Metal Verifier
For the next test I break out this handy little gadget made by Sigma metalytics.
http://sigmametalytics.com/
This device uses electromagnetic waves to test the metallic properties of the piece. It can test gold and silver of various purities as well as platinum and palladium (and others).
This coin checks out!
Step 4: Ultrasonic Thickness Gauge
Ok, here is where I break out the big guns. For my larger and more valuable bars I'll test them with an ultrasonic thickness gauge.
This device can measure the thickness of many types of material using the power of sound! You just need to know how fast sound travels through the substance you are testing. Sound moves through silver at 3650 meters per second, which I've set here (for gold it's 3240 m/s)
Measure your bar with a digital caliper. This one is about 25 mm.
Grab yourself a bottle of Thera Sonic Conductive Gel.
Squirt a blob of this onto your silver bar. (It won't hurt the silver.)
25 mm, seems legit!
There are some other tests you might do, like water displacement, the ice test, or the ring test. I don't usually do these.
I hope this helps all your silverbugs out there!
