In the past, Silver Investing News has looked briefly at how to avoid and identify fake silver coins, but Dave Martinez at SilverCoins.com recently put together a more extensive overview of how to do so. Here are a couple of the most interesting tests he mentions.
The ice test:
Cheap and easy to do, getting some ice from the freezer is a simple way to test both silver coins and bars for authenticity. All you need to do is place the ice on the silver and watch.
The ice should begin to melt immediately, this is because silver is the best conductor of heat for all the metals. Below is a chart on thermal conductivity amongst popular metals. You will see that silver tops them all even including copper which is the most popular metal to use.
The bleach test:
Another cheap and simple way to test for real silver vs. fake is to use some household bleach. Silver will tarnish very fast when exposed to any sort of oxidizing chemical like bleach. All you will need is just 1 drop, place it on the silver and if it begins to turn black then you can check it is silver. (Silver-plated items will also pass this test).