Loss Of Weight Of A Coin ?

Yes, a recent edition (2016) of the Gobrecht Journal contained just such a study. It was quite interesting and might be available on their website: http://www.lsccweb.org/Gobrecht_Journal.php
If you can't find it let me know and I'll try to scan the results and post them here.

The problem with trying to determine weight loss from circulation is you need to know the exact weight of the coin when it came from the mint, and its current weight now that it has been worn from circulation. You can't just assume the official specified weight because of mint tolerances. You don't know if the coin was orignally right on spec, on the high end, the low end, or heck it might have even been out of spec high or low. So the only thing to do is start with some brand new coins and record their exact weight, then release them into circulation to let them get worn. This leads to the second problem, how do you find those exact same coins now that they are worn so you can re-weigh them?

Conder101 has a good point and that's why many hundreds need to examined and the results averaged out similar to the mint weighing bags of coins to get a standard weight.

I'll see if I can find the issue with the weight loss article and scan & post it.

If I were doing this, I would get a couple dozen rolls of quarters, weigh them, calculate the weight loss against the spec, and divide by the number of years since minting. Once you hit a few hundred coins, it should be a pretty stable statistic. While you are doing this, pull out the silver and keep it as compensation for your time. Return coins to bank and make a post. Who wants to volunteer?

Here is the article written by Liberty Seated Collector's Club Vice-President, Leonard Augsburger. The article was published in Summer 2016 edition of the The Gobrecht Journal.

If you are not a LSCC member you can join for only $25/year, the Best Value in Numismatics. Members receive three issues annually of the award-winning Gobrecht Journal and the monthly electronic publication, the E-Gobrecht. In addition, the LSCC attends more than 20 regional events each year, providing educational programs, exhibits at Club Tables, and meetings. More info here: http://www.lsccweb.org/Membership.shtml

Kind of nice for his to do that, but posting the whole thing like that IS a copyright violation.

It was a very interesting article. I was surprised that just a few types made up the majority of the Seated coinage in circulation.

Well if you are only concerned with time then its easy, change in weight is zero. Take a new coin put it in a box and wait 100 years and it will be the same weight when it comes out as when it went in. If you are concerned with weight loss in circulation then you are talking about wear, and wear makes it a reference to grade. If he is trying to ask how long does it take in circulation to lose a certain amount of weight, you have the problem that coins often don't circulate continuously. They circulate, then they sit for awhile, then they circulate some more etc. I have pulled coins from pocket change that were 50+ years old and still AU, and I have pulled some less than 20 years old that were VG. Time doesn't matter, the amount of wear, the grade, is what matters as far as weight loss.