Gyrogami Blog - Precious Metals, Jewelry, Artwork

Silver has a Mohs rating of 2.5 for dead-soft to maybe 3.5 to 4 for work-hardened pieces. Lead has a rating of 1.5. The fake silver alloys, aside from lead-based ones, will usually be harder. Most of us don't have access to sophisticated testing equipment but common sense and some known purity samples help identify fakes.

This differs from the heat or cold test listed in Part 1. Primarily useful for lead-based bars, it will destroy them. If a bar is lead-filled or primarily composed of lead it will melt away long before it should. Filled bars can be dangerous since the core may turn liquid or gas before the outside melts, potentially exploding. The color of the metal after heating can indicate the presence of some elements as seen in the next test.

This differs from version 1 due to the amount of heat you will be applying to the piece. Use it only after it passes version 1. Pure silver will not tarnish or discolor when heated with an air-aspirated flame. As the presence of non-silver metals increases, the piece will change colors (oxidize) as it gets hotter. Heat it to red hot for this effect to be pronounced. Pure silver will have, at most, a white coating on it after water quenching but lesser purities will have more coloring.

The acid test is a popular and reliable home method but most people incorrectly use it though 100% of them think they are right! The acid always turns red on a silverplated item. Wipe it off and repeat six or seven times in the same spot, letting the acid sit for 15-30 seconds each iteration. If it is still red, it is silver or the thickest plating known to man. Regarding silverplated turning red, a simple analogy is testing particle board for the presence of wood. Burning a small piece will absolutely smell like wood but it is particle board, not solid wood. Ergo, the presence of silver on the surface means it is silverplated, nothing more.

The gouge method tests some shavings from the piece. There is no going back. The scratch test, while not as damaging as the gouge method, requires rubbing the piece against a test stone to which the acid is added. Silverplating will give a positive test if the underlying base metal isn't reached. If the scratch spot is carefully chosen, it can be hidden with a little polishing or TLC.

The last resort would be to drill or cut the piece for a visual inspection. Take a sample from the middle of the piece and use an acid test or one of the other testing methods. Use them all if necessary.

The last LAST resort would be a fire assay. The piece is melted down and a series of special tests are performed on it. It requires an exceptionally accurate scale, a decent furnace where temperature can be controlled, and the means to make and pour ingots.

The other last LAST resort would be refining. You will get pure silver in the end.

Titration and its kinfolk come to mind. Sending the ingot or sample through a refining process would also qualify. Aside from refining, which is the goal of acquiring most precious metals, they are useful but not feasible for our needs.