What kinds of silver metals are there out there? It can be difficult to figure out what is made from nickel, or copper alloy and even Alpaca for the amatuer collector.
Here is just one article about the topic, feel free to add more informative links to this discussion.
What are Nickel Silver, German Silver and Alpaca? Don't Be Fooled by These Silver-colored Metals
By Pamela Wiggins
So you find a piece of jewelry or an old metal object for a good price that looks a lot like silver. Being an astute picker, you look for clues to identify the piece and discover that it’s marked nickel silver, German silver or alpaca. But does that mean your item is really some form of silver? Unfortunately, no.
What is Nickel Silver and German Silver?
The terms “nickel silver” and “German silver” refer to the same substance, but items made of this metal aren’t really silver at all.