The heart of coin collecting is the weight of the precious metal in the coin. Coins are minted to precise dimensions and bear the marks of governments to help simplify the exchange of precious metals.
Despite the historical significance of the marks, the real meat of coin collecting is the amount of precious metal in the coin.
Since the mass of the coins is of primary concern, the very first step one should take before buying coins is to get a scale.
The first step in buying a scale is to figure out the precision of the scale.
Coin collectors often measure the specific gravity of a coin. This involves measuring a volume of water that is several times the weight of the coin. A silver dollar weighs 26.73 grams. A troy ounce weighs 31.1034768 grams. Your coin scale should be able to weigh a mass several times this amount. You want a scale that can measure 100 grams or 200 grams.
Precision matters. To weigh coins, you will want a scale that can measure to a hundredth of a gram. When shopping for coins, you will often find pocket scales listing dimension like 200g x .01g or 100g x .01g.
Food scales (those used for cooking) usually have dimensions like 1000g x 0.1 grams. These scales don't have sufficient precision to measure the specific gravity of coins.
You can find pocket scales that measure to the right precision for under $20.
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