How do you tell the proof from the non proof on S mint coins from the 70's? before they were made all proof? thanks
Proof coins will have a mirror finish in the fields and sharper details than a Business Strike. Look for more detail in things like hair, squared off edges and full rims on Proof coins.
Then you would have an impaired Proof. Unless the coin is heavily circulated there should still be some mirror in protected areas (e.g., inside letters and numerals) and the edge should be more square than a Business Strike. Look for any clues that would indicate the coin is either a Proof or a Business Strike.
Isn't a proof coin stamped up to 8 times wherein an unc coin is stamped only once for identification? And isn't the preparation of a proof coin completely different designed for collecting rather than circulation?
If the coin looks basically like your average circulated Lincoln, then it is one. The mirror finish on the proof coins is the primary give away to identifying the modern proofs. As Hobo said, look at areas that wouldn't be rubbed by normal handling like inside the 9 and 0 in the date, near the word Liberty, etc. There would be some mirror finish left in these areas even on a heavily circulated example.
A Proof coin is struck multiple times (usually 2 or 3 depending on the denomination) to bring up full details - not for identification. Not different, just more carefully. The planchets and dies for Proof coins are prepared with more care and the finished product (the Proof coin) is handled with more care than for Business Strike coins.
hmm ok. The one I havent doesnt really have that... although it still shows some red near the inside rim. it also had those lines running through it (not from being cleaned) - you know what I mean? That I've seen on other proof cents...
Aren't the planchets polished like the fields of the dies on the proof coins , and then struck with more pressure ? rzage
yes, but not every proof is. I was using the absence of any mirror finish as a diagnostic, and pre-1950, that isn't true, but I was trying to offer help for his 1970-S coin.
Are you referring to Matte Proofs? The Mint made Matte Proof coins beginning around 100 years ago and up until they stopped making Proof coins entirely around 1916. Proof coins had a mirror finish before and after Matte Proof coins. I have several 19th Century Proof coins with nice mirrors. When the Mint resumed Proof Coin production in 1936 the first coins were not brilliant Proofs like modern Proofs (but I don't think they were Matte Proofs either). After complaints from the public the Mint changed their production to brilliant Proofs like we know today. So pre-1950 Proof coins have a mirror finish except for the Matte Proofs made for a few years and the early 1936 Proofs (and perhaps a handful of other exceptions).
A lot of the nickel alloy proofs from the 1860's to 1890's have little mirror finish as well. It can be very difficult to tell mintstate and proofs apart from that era. Even the TPG's frequently get it wrong.
yes, hobo, I was referring to the matte proof and satin proof issues when I stated that not all proofs have a brilliant finish. What I was trying to do in my response to Magman was to help determine if the 1970-S was a proof coin. I used the mirrors as a diagnostic for that coin because all proof 1970 coins were struck with brilliant surfaces. I fully realize that the mint has made proof coins for over 150 years and the predominant finish has been a brilliant (shiny) proof surface on the coins, but I was focusing strictly on 1970. The exception to the brilliant finish was a matte or satin finish used early in the 20th century. These can be difficult at times to discern from circulation strike coins, but have other diagnostics such as sharp edges, and deep detail.
