Okay! So, now what?

I'm preparing to consign some medals to a friend of mine on eBay. Most of these are from private mints here in the states, and some of them do not identify the metal composition. I didn't think this would be a problem because I always thought that it was easy enough to identify silver from white metal using a magnet, though I've never bothered trying this before.

Anyway, I separated all those that had the "heft" of, say, a silver dollar or half dollar and started checking them with a magnet. When all of these medals proved to be non-magnetic, I started questioning this method. So, I tried using the magnet on some clad quarters, and I discovered that all of them, too, were non-magnetic.

What should I do, now? I don't want to test any of these in a way that could damage them, and I certainly don't want to spend $10-15K on a fancy machine like they did on "Hardcore Pawn" . Does anyone have any suggestions?

Chris

 

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What about weighing them with a very precise scale? You can list them as composition unknown/uncertain, give the diameter in mm and weight in grams and let bidders figure it out. Is there a website online that you can link to in the listing that notes composition, etc.?

 

What about take your time and research each of them individually? Chances are your medals are not unique, so you should be able to find others alike. Google, ebay, books, or post here. Don't sell anything without having a precise understanding of what you are selling.

 

I never understood the magnet testing thing. Been hearing talk of the earth magnet slide test. Not sure what that is either.

 

I've owned most of these medals for 10-15 years. Trust me! I've researched them many times before. I started collecting medals about 20 years ago, and I've found that many of the private mints don't keep records. It is harder when you don't know which mint produced them or even the designer's name (who was usually an employee of those mints.)

I've also found that the mintages of so many medals produced before the advent of the internet were generally very low......less than 500......so it's not like you will find them listed on eBay that often.

Like TC suggested, if I can't determine the composition, then I will just have my friend list it as "Unknown".

Chris

 

use a test stone and a bottle of a acid, the stone won't hurt the edges, and you can put acid on the metal traces left behind instead of on the coin.

 

You could see if any of you local coin stores have one of the "fancy machines". I know at least 2 stores in my area have them.

 

What's that?

 

I use a Rare Earth magnet about once a week,although it will not indicate the purity it will show the difference between a 999 coin and say 925 British Crowns and 900 Morgans and will slide right off a non silver coin..
The magnets are very cheap to buy, I got 7 on eBay from China for little over $10 & free shipping.
This Youtube video shows how its done.

 

Personally, I wouldn't trust anything from China.

Chris

 

BTW if you think it might scratch the coin then wrap the coin in cling film, it works the same.

 

Your choice, I also bought two from the UK worked just the same but more expensive.

 

While this is true, it's not exactly something that's very easy. To do it appropriately (at least that I've seen) you need to have a very precise way of measuring volume displacement. That usually means submersing the piece in water, measuring the amount of water displaced. Then weighing the piece in grams. This will allow you to get the grams / cubic centimeter density of the metal.

The ratio of the density of the metal to the density of water is the "specific gravity" (also called the relative density). But you can ignore that part, and just compare the density of the metal you find to the density of known metals. Based on the tables I can find, white metal has a density of 7100 kg per cubic meter. Silver has a density of 10490 kg per cubic meter (link here).

But, as I already said -- while this test will give you an idea of the metal content -- it is quite laborious and (quite frankly) not very feasible for a large quantity of medals.

 

The method above is very difficult unless ones has lab devices that can measure volume in thousandths of a millimeter. However, the actual definition of specific gravity is

weight of object in air
_________________________
weight of object in air - weight of object in water

so a device which eliminates the need to measure microscopic volume can be easier to use. This device below is a nice setup for very inexpensive price ( compared with true lab equipment. You can buy without the balance or with.

http://www.mineralab.com/Scale.htm

 

Regardless of how you measure it (displacement, or weight in water), you would need to submerse the medal in water, correct? That's the part that I don't think too many people would be keen on doing. It's tedious, especially for a large quantity of different medals. Another thing I don't like about the "weighing in water" part is that the water temperature needs to be controlled (or at least accounted for in the equation) to get precise measurements.

Long story short, while the specific gravity method gives a good answer to the question, it's so tedious and cumbersome that I would almost never recommend it in actual practice for a coin or medal.

 

But is there anything between it and a XRF analysis ( which is limited to surface) that is nondestructive ( certainly acid or chemical tests on the medal are not)? Yes there is a correction as the definition assumes water at 4 degrees C, but this is almost exactly the 40 degrees F. that water in a refrigerator would be. It is better than the drop-ping test, chemicals , or 'slide' test, IMO. A 30 second under water would not be dangerous to the medal unless it was water soluble.

I do specific gravity for minerals, and the longest part ( once set up) is to do the math on a calculator. But just my opinion.

 

I agree there is no middle ground. I don't like the acid tests for the reasons you stated. The submersion of the medal under water isn't dangerous, but being certain you don't cause any damage in the drying process is always a danger.

If it were me, I'd be using a good dose of Google to research each piece. Even if they are 20+ years old, from private mints, and quite scarce -- if a medal was only made in silver, then you don't need to test it.

If I had one or two medals that I thought were very scarce and valuable, I'd do this specific gravity test. But, for 20-30 medals, especially if modern (regardless of mintage), I'd say screw it.

 

Most of these medals are 35-75 years old, and I have about 50 of them.

Chris

 

Wow that's a lot of medals. Most people bidding on these will likely not be doing so as a bullion play. I am sure enthusiasts will know what they are and bid accordingly.