On older costume jewelry, the earring posts may be gold, most likely only gold plated. The reason they are is because gold does not react with the human body, it's a Noble Metal and thus doesn't react with very many things at all. More than likely now days, it's some other metal or alloy or plated metal that doesn't react with the human body. Whatever works and is cheapest. So it just simply depends when it was made.
Same on the dental jewelry. It could be Palladium, Platinum, Silver or an alloy of any of them, it may or may not be alloyed with mercury. Older dental work, such as fillings, were alloyed with mercury because it made it malleable. But most of the bridgework, if I remember correctly, does not actually have mercury involved because it's not desirable for it to be malleable. The reason why your local pawn shop isn't purchasing dental metal might be for several reasons. First, it's almost never one type of metal because gold, silver, palladium, etc are all malleable to a certain degree. However when alloyed they become stronger and less malleable because the way the metal crystals lay together, one type of metal fills in the gaps the others metal crystals leave behind thus making it stronger than either alone. When refining this type of material, it costs more because it's more difficult to separate the alloyed metals. To do so requires that one type of metal be added, in most cases silver, up to 95%, and then refined as a silver proposition. The dental work you have is probably not silver, but most likely some alloy of palladium, platinum, gold, etc. So if you can imagine having to add enough silver to make the total amount of silver 95% or better so it can be run in a silver electrolytic cell is not only time consuming but can be expensive. Or if not, it is melted into a homogeneous mass, poured through an atomizer to reduce the metal into a fine sand, and then digested selectively in acids to part the metals from each other. Refineries generally prefer to run clean material as it's not only easier, but more cost effective. They do not pay full value on alloyed metals, even if you are asking for a full accountability.
If the Pawn shop has no way to do an assay, they would have no idea what types of metals the dental work is composed of. A regular acid test will not tell you, neither will a scwartzers solution unless you know what you are doing and have a lot of experience and even then you would not be able to tell the percentages. So how is the pawn shop broker to know the composition of your dental metal, and then how are they to know how much of spot the refinery will pay due to the difficulty of processing the material. If you have pure Palladium, most refineries will pay about 90% spot, but if it's alloyed with Platinum, they might only pay 60% spot on the Pd, and 70% on the Pt (Palladium/Platinum). The broker has no idea what the alloyed metals are, or what percentages they might be. Every dentist has their own mix they prefer to work with.
Best thing to do is find someone that deals with dental scrap, or send it out to be assayed by a professional assay lab. Personally, unless you know a refiner willing to deal with dental scrap, I would save it up until you have a large quantity of it and sell it on
ebay, probably less hassle than trying to have it refined.
Just for reference, there are three main types of dental bridgework as I understand it. Full porcelain, porcelain fused with metal which looks like what you have in the picture, and full metal which is far less common.
Scott
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