Gold and Silver Coin Collector Toolkit

Collecting gold and silver coins can be a great hobby. Not only that, but over time the value of your collection will rise as the gold and silver prices rise.

I hunt for interesting items in online auctions, in antique shops, in second-hand shops, in street markets and in pawn shops. You never know what you are going to find or where.

Last week I popped into a watch shop in Crans Montana, Switzerland and asked if they had any coins. They had a $20 Gold Double-Eagle coin from 1904. Whilst millions of these coins were minted, most of them were melted and turned into bars in 1933, due to President Roosevelt's Executive Order requiring all American's to hand in their gold. It's not clear how this one survived, but it's a fascinating find.

CoinSnap

Whilst most gold and silver coins cost more than the value of the gold and silver they contain (known as the "melt-value"), it's useful to know the exact specifications and metal content. I don't like to pay too much of a premium over the precious metal content. To know the specifications of the coin, I simply take a photo with an application called CoinSnap. If it is successful in identifying the coin, it will give me the precise specification. My coin contains 30.1g of gold with a melt-value of Sfr 1754.

The cost of CoinSnap is $20 a year.

Pinger

When you buy a coin you need to know if it is really solid gold or silver. One of the oldest tests in the world is known as the "Ping-Test". You strike the coin and see if the "ping" sounds right. To get the perfect ping, I use a "Pocket Pinger" and a wooden baton, as shown in the photo. The Gold Double-Eagle pings for around 14 seconds while the Silver Victoria Jubilee Crown pings for around 8 seconds. A tungsten-filled gold plated coin won't ping at all. A pocket-pinger such as the one shown in the photo costs around $8.

CoinTester

If your ears aren't sufficiently tuned into the ping sounds, you can use an application called "CoinTester" to listen to the ping and tell you if the ping passes or fails. CoinTester costs $3 a month.

Magnet Test

There are two types of test here. The first is the attraction test. Neither gold, nor silver should stick to, or be attracted by, a magnet.

The second test only works with silver coins. Allow the coin to slide down the magnet when held at 45 degrees. It should slide slowly. A cupro-nickel coin would slide fast. If testing a bar of gold, you can let the magnet slide down the bar.

Scales

Compare the actual weight of the coin with the expected weight.

Digital Calipers

Use these to verify that the diameter and thickness of the coin correspond to its official specifications.

Diamond purity tester

Whilst this is not strictly for testing metals it will tell you the approximate purity of the surface of a coin or bar. For example, a 99.9% pure silver bar would show 12 bars. A 92.5% pure coin would show 10 or 11 bars a 50% pure silver coin would show 5 or 6 bars, and a modern cupro-nickel (75% Cu, 25% Ni) coin just 2 or 3 bars. An early silver Roman silver denarius from around 43AD showed 9 or 10 bars, whereas a later denerius from 100AD showed 7 to9 bars, and a more heavily debased denarius from 177AD showed 6 bars, and one from the year 211AD showed only 5 bars.

The diamond purity tester costs around $8.

Specific Gravity Test

Invented by Archimedes, this test is not only free, but it is possbly the most reliable especially when dealing larger shapes such as ingots, or un-even shapes such as jewellery. All you need is a container (I use a plastic milk-bottle with the top cut off), some dental floss, some scales and some water at 20c. Weigh the bar. Place the container of water on the scale and zero it by pressing the tare button. Suspend the coin or bar in the water using the dental floss. Do not let the suspended silver bar touch the sides or bottom of the container. Note the reading-value on the scales. Divide the first number by the second, and compare the result on a table of specific gravities. Pure silver has a specific gravity of 10.49, whilst pure gold has a specific gravity of 19.32

Cotton gloves

Silver coins react to finger-prints. If you are handling new shiny silver coins and want to preserve the surface, always wear gloves.

Coin Capsules

Silver reacts to the sulpher in the air. That's what creates the patina on older silver coins. Putting the coins inside a capsule will help to preserve the sheen and also protect against accidental damage from knocks,scratches, and liquids.

Loup, or magnifier

You'll see far more detail (and blemishes) on a coin if you use a loup. The cost is around $5

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