No, this is not correct. Perhaps the author of FAQ for the mint wasn’t even around in 1975! But, this is not correct…at least for the quarter dollar. Usually, the coin collecting tri-fold books (esp. Harris) will state the number in circulation. I’ll go pull my “Quarters” book from my collection…
OK, you can shoot me now! It was 1971 that is significantly less than the avg population in circulation! Sorry, sorry!
Quarters, Halves and Ike Dollars, there are zero stamped 1975. None, not a one. Not only do the books not have the slots for them, the guides don’t show any minted. Not a one.
What you really want to look for now is pre 1964 quarters.
They are worth almost 10 US Dollars each now because of their silver content.
The vast majority of silver Washington quarters are worth about $2 each.
We’re paying $7.50 each as of Saturday. So, let’s split the difference. 
Here are some quotes from today on silver quarters. Four Hundred quarters for $3,700 plus. This equals well over $9.00 each.
If you have any, I’ll gladly pay you $2.00 each for all you have.
$100.00 Face Value
Bag of U.S. SILVER QUARTERS
Lot of 400 US silver quarters
Contains mixed dates 1964 and before.
Coins are in various circulated grades, with 95% or more showing readable dates. Each group we sell has a different assortment of dates. Coins are in a cloth/canvas type bag.
FREE shipping !
Quantity In Stock : 2
PRICE : $ 3,756.00
$1000 face (Full bag)
$36987.98
$500 face (1/2 bag)
$18623.32
$250 face (1/4 bag)
$9259.93
$100 face (1/10 bag)
$3724.66
$10 face
$382.05
$10 face halves
$400.17
Where? And since I know you’re not local to me, what do I need to look for in the phone book to find a place that might buy such things?
How much actual silver is in a pre-1964 quarter? I’m getting that they were 6.25 grams and contained 90% silver, so that would be .19 oz. If this is correct, 5 quarters would make an ounce of silver at I think $46.00 per oz. today.
Am I doing that right?
No.
U.S. 90% junk silver is bought and sold by face value, usually in $1,000 face-value bags but also in bags of $500, $250, and $100. It sounds complicated but it’s really quite simple. A full $1,000 bag contains 2,000 half dollars, or 4,000 quarters, or 10,000 dimes. It weighs 795 oz., regardless of whether it’s made up of dimes, quarters, or half dollars. Because each coin is 90% pure silver by weight (plus 10% copper, added as a hardener), a $1,000 bag contains 715 net oz. of pure silver—-again, regardless of the denomination of the coins.
$100.00 Face Value 71.5 oz.
$10.00 Face Value 7.15 oz.
$1.00 (4 quarters) .715 oz
Call any coin dealer in your phone book. You’ll certainly find lots of quotes, some wildly low, hopefully some within reason. A quarter melts today for about $8.
I seriously doubt that many coin dealers are paying what we are–$7.50.
If you can get $6 or better, take the money.
1964 US quarters are also silver. It’s the ones 1965 to present that are not.