Hi all, I recently got into silver stacking and I am curious about what different testing methods everybody uses. I have done some research and found several different methods and it seems that it is best to combine multiple methods to be sure. The most expensive but effective method from what I can tell is the testing machine called Sigma Metalytics. Curious how many people have gone done this route and think it is worth it? My plan is to do the following, any comments or feedback on this would be appreciated: - visual inspection - caliper measuring the diameter and width - weighing with a scale - using a rare earth magnet to do the 'slide' test - lastly doing the 'ping' test using the Bullion Test app on my phone As far as the ping test app goes I am wondering if people think it is effective and I found a few different apps on the Play Store. Are any of them more reputable than others? The one I am using is called Bullion Test and I believe it actually started on this forum. The other ones I saw were called Precious Coin Tester and Pingcoin. Just wondering if I am using the best app? Please let me know what you use and if these tests I have listed would be good for determining silver, from what I have seen the magnet test is effective but if I have been looking at the wrong resources please let me know. Thanks!