Avoir dupois weights   The system of masses used in the United States for most common commercial purposes based on the pound and ounce.   Troy weights   A system of mass units use to measure precious metals. While there are 16 avoirdupois ounces in one avoirdupois pound, there are only 12 troy ounces in one troy pound. Grams as well as grains are equal under both systems.   Conversions   1 gram = 15.43 grains 1 ounce troy = 31.103 grams = 480 grains = 1.097 avoirdupois ounces 1 ounce avoir dupois = 28.349 grams = 437.50 grains = .911 troy ounces   Sterling vs. Fine silver   The two most common forms of silver are Sterling and Fine Silver. Sterling silver is 92.5% pure and fine silver is 99.9% pure. One troy ounce of fine silver weighs 480 grains. One troy ounce of sterling (.925) silver also weighs 480 grains, but only contains .925 troy ounces of fine (.999) silver. Conversely, 1.04 oz of sterling silver contains 1 troy oz of pure silver. Frequently, Sterling silver coins or bars are weighted to yield a full ounce of .999 silver - they weigh 1.04 troy oz to make up the difference. 90% silver (junk silver) is the cheapest form of investment silver. The price is based solely upon the silver content of the coins. Fortunately, a given face value of any coin, whether a quarter or a dime, yields the same silver content. Because $100.00 face value in dimes contains the same silver content, 71.5 troy ounces, as $100.00 face value of half dollars or $100 face value of quarters, the calculation is the same for all denominations. U.S. coins minted prior to 1964 were composed of 90% silver and 10% copper. The main reason they are known as survival coins is the fact that they are legal tender coins. Also, because people remember when they circulated as money, they have the advantage of being easily recognized as money. If the need arises to use these coins in everyday transactions, Americans will feel comfortable accepting them as payment for goods and services. Additionally, because they are denominated in convenient amounts, they will work well in trade. A full bag contains $1,000 face value of dimes, quarters or half dollars. A bag of dimes contains 10,000 coins; a bag of quarters 4,000 coins; and a bag of half-dollars 2,000 coins. When minted, a $1,000 face value bag contains 723.4 ounces of silver. Due to wear, however, a bag of circulated coins yields approximately 715 troy ounces; therefore, to calculate a price, multiply the weight (715 troy oz.) by the spot price of silver. Different dealers use slightly different constants for this calculation. For example, thesilverXchange uses "715" as the constant whereas other dealers may use "712" or even "700". A full bag is $1000.00 in face value and contains approx. 715.0 troy oz of pure silver. A half bag is $500.00 in face value and contains approx. 362.50 troy oz of pure silver. A 1/4 bag is $250.00 in face value and contains approx. 178.8 troy oz of pure silver. A 1/10 bag is $100.00 in face value and contains approx. 71.5 troy oz of pure silver. A roll of dimes face value is $5.00 and the silver content is 3.50 troy oz. A roll of quarters face value is $10.00 and the silver content is 7.00 troy oz. A roll of half-dollars face value is $10.00 and the silver content is 7.00 troy oz. One additional consideration is important. Half dollars are generally more in demand than quarters or dimes so they carry a premium on their price. Also, the older half dollars, such as Barbers and Walking Libertys, carry a premium over their newer counterparts. the Franklins and the Kennedys. Among quarters and dimes, the same preferences apply between oldest and newest.