Pictures What Weight Limits Grains Or Grams

Hi mishap and welcome to the forum! You'll find us to be friendly folk and collectively loaded with lots of knowledge and experience.

I can partially answer your question with examples from my own Morgan collection and with info from a previous thread that dealt partly with this subject. A rough rule of thumb is minus five percent of the specification weight as stated by the mint and most of this would be due to circulation wear. I don't believe you'll find a "plus" weight in an authentic coin since there is no way to add metal to a planchet and densities are tightly controlled. I don't have the specs for modern coins although they may be found in Coin Prices magazine and online sources.

For Morgan silver dollars, the specs state 412.5 grains (26.730 grams; my scales measure in grains). My Mint State Morgans (those that I weighed before grading and encapsulation) all weighed just about that with little variation. I have an 1879CC which is very well circulated (G-06 at best, more likely G-04; it's a problem ["environ. damage"] coin, so I use it as an educational and experimental tool). It weighs 398.2 grains, or 96.53 percent of its original weight. Similarly, I have a counterfeit Morgan which weighs 380.0 grains (92.12% - not a difference one can measure by feel), significantly less than an authentic Morgan, Mint State or circulated.

While 5% off a cent, nickel, dime, etc. may not seem like much, it is still detectable with a good scale which goes to three decimals in grams or one decimal in grains. Any weight difference beyond this would draw heavy suspicion on a coin.

I hope this answers your question although it's in a bit of a roundabout way.

Fred

mishap-coins - The question you ask likely has an infinite number of correct answers. There are several variables you need to consider.

Country of origin - many countries are notorious for both underweight and overweight coins at different times. So knowing what is "normal" for a given mint will vary with location and time. Spain in the colonial era produced silver coins that were as little as 50% of the correct weight and assay. They were closer to tokens than to specie.

Metal used for specie coins - those made with precious metals are more likely to fall under tighter quality controls especially in the modern era (after improvements in presses were introduced). But before the steam press was invented, I can point to many coins where too much metal was actually used to make coins - one of my favotite series the Profile Eagles from Mexico show weights of up to 2-4 % too high in 1823 and 1824. But if you look at copper and bronze pieces the "correct" weight can be all over the place. For example what about the "Dump" coins of India?

Modern US coins - will be far more controlled but the more recent clad coins can be considerably underweight if you include minting errors caused by defective planchets. The mint has less incentive to get the coins precisely correct since the value of modern coins has no relation to the metal content.

Wear - I agree with Morgan Fred regarding how much metal is lost through circulation wear. Five percent loss will pretty well eliminate the design of most coins. Modern coins are not "high relief" because that causes production problems. In the old days, banks and merchants actually weighed your coins before crediting them to your account or purchase. Silver coins were weighed up to about 1890 and gold coins were weighed up to 1933 in the US anyway. Just because your coin had a face value of say $10 didn't mean you would get that automatically. Most banks (according to my sources) pulled gold coins when they reached about 97 percent of full weight. Silver coins were not intrinsic based after 1890 when world silver prices fell.

From your name - I presume your real focus is on minting errors. Good luck in that arena.

But if you ever run into counterfeits drop me a line. They are most normally underweight.

I found the following on the error web site:

http://hermes.csd.net/~coneca/conte...lossary.html

Sintered
These planchets were kept too long in the annealing drum. While in the drum, they became coated with a layer of metal dust which the heat then sintered onto the planchet. These are known with partial, single-sided, and double-sided sintering.

Based on my reading of that definition - I would presume that the added dust would increase the weight of the planchet, but how much?