6mm x 6mm
Pure silver is 99% pure silver metal. If you buy an ounce of silver in a bar then what you are getting is 99% pure silver. Unfortunately, 99% pure silver is not hard enough to be suitable for a jewelry metal. This is why we have 925 sterling silver. This is a metal that is 92.5% pure silver, so you can see where the 925 comes from. The rest is usually copper or some other alloy.
Here are some signs that your jewelry is made from something other than 925 sterling silver:
Of course, price isn’t a very good indicator because unethical sellers will tell you it is 925 sterling silver in order to get a higher price than the jewelry is worth. So, if you are jewelry shopping, it is a good idea to have a magnet in your pocket to test anything before buying it. Of course, you would not need to do this in a fine jewelry store, but you would at the swap meet or to test a questionable piece of jewelry anywhere.