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Mint paid only 14-cents per pound for "old pennies."

This Denver Mint letter indicates the mints bought "old pennies" for a tiny fraction of face value. Wonder how many hit the furnace at 14-cent a pound?
[NARA Denver RG104 E-22 box 1 via NNP]
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Comments
Pennies per pound
A penny weighs 0.0081 ounces. Twelve pennies weigh approximately 1 ounce, and 182 pennies, or $1.82 in pennies, weigh approximately 1 pound.
The more qualities observed in a coin, the more desirable that coin becomes!
My Jefferson Nickel Collection
No. An 1864-1942 cent weighs 48 grains. An avdp. oz. weighs 437.5 grains. 16 avdp. oz. = 7,000 grains. 7,000 divided by 48 = 145 and a fraction cents.
Bulk pure copper was 18 cents a pound. Paying 14 cents per pound for small lots of alloyed and possibly corroded or contaminated copper was very fair. If the lady wanted face value, she should have spent them! The Mint was not a Coinstar machine!
I can only assume she just wanted new, clean cents in exchange....No idea why else she would attempt such an exchange...Too bad the submitter's letter is not available. I wonder what quantity was sent back? Lots of questions.. Cheers, RickO
In a follow-up letter, the Superintendent wrote that the original contained 130 pennies and that 15 were used to pay return postage.
It is likely the "pennies" were either large copper cents or copper-nickel "white" cents. Absent the word "nickel" in either letter, I suspect the coins were large coppers. (All small cents were legal coin even if corroded. Large coppers were not.)