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. Dust has a rating of 6.5 to 7 which explains why rubbing a silver or gold piece can leave fine scratches. Most of us don't have access to testing equipment like this but a little common sense and some known samples can help rule out some fakes. Machines like this start around $1000.

This differs from the heat or cold test listed in Part 1. Primarily useful for lead-based bars, it will destroy them. Lead has a much lower melting temperature than all precious metals. If a bar is lead-filled or primarily composed of lead, it will melt away long before it should. It is necessary to have some control over the flame or furnace temperature. 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 (neutral, propane is easiest) 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.

Videos of this type of testing will be uploaded soon.

The acid test is the most popular and reliable home method but 99%+ of people incorrectly use it though 100% of them think they are right! The acid always turns red the first time 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. The test site can be polished almost as good as new. 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 not a correct assumption to say it is solid wood because it is particle board, not solid wood. Ergo, the presence of silver means nothing more than the presence of silver and is no guarantee the entire item is silver.

Videos of this type of testing will be uploaded soon.

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. Even more people do not know how to do this method than the acid drop method but still, 100% of them think they are right.

Videos of this type of testing will be uploaded soon.

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. Special one-time use crucibles designed for this purpose are sometimes used depending on the metal being assayed.

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.