This list gives approximate weights in grams of American silver coins prior to 1964. It is important to note that pre-1964 American silver coins contain 90% silver, not 100%. There are 31.1 grams in a troy ounce. Silver is bought and sold in troy ounces on the commodities markets.
Coin Type
Grams
Silver Dollars (pre-1965)
26.7
grams
Half Dollars (pre-1965)
12
grams
Quarters (pre-1965)
5.8
grams
Dimes (pre-1965)
2.5
grams