All metals are sourced from trustworthy sellers and have passed my rigorous authentication through several steps in the following order whenever appropriate:

1. Weight test
2. Magnet test
3. Ice test
4. Ping test passed by iphone APP StackerTools.
   • This is an overly rigorous test which sometimes fails a legitimate piece of silver in an odd shape or heavy toning.
5. And/or the test of Sigma Metalytics Precious Metal Verifier PMV PRO with Refiners Wand, Small Wand, Large Wand and Bridge (Model #2701):
   • This device tests the resistivity and density of metals. It cannot tell you what a piece of metal is. It can only tries to tell you if that piece fits what you think it is. You have to have a rough idea what the piece can be.
   • It is one of the best ways to test authenticity in general, but it cannot replace other kinds of testing, and is not always the right/best way of testing (NOT infallible, and limited in the testable range of metals):
     • In rare cases, a fake piece of metal can have similar resistivity and density of a real piece thus fooling Sigma.
     • A genuine metal piece may fail Sigma test because of its extreme size, lack of flat surface, toning, and other interferences such as assay card with authentication technology. For example, a genuine PAMP 1 gram Fortuna Gold Bar fails the test of Sigma PMV Pro with all accessories due to its extremely small size and the interference of its Veriscan Assay Card.
     • This device cannot test silver with a purity lower than 83.3%. For example, 40% silver Kennedy Half Dollar cannot be tested by Sigma, but can be tested by ping test through StackerTools.
   • Thus, my multi-step hybrid authenticity test is superior than only using Sigma, and is the best practice given my resources. There are other even more expensive tests - XRF can outright tell you the exact metal composition of the surface of a piece of object, which Sigma cannot do. But the penetration of XRF is shallower than that of Sigma.