How do you tell the difference between a mint coin and a proof coin? With the exception of the ones that were only made in proof.
Both are mint coins, in that they were made in the mint. The one you call "mint" I am sure you mean as Business strike graded as MS ( mint state) when produced, where as proof coins often have a differential surface. They can have the brilliant reflective surface similar to a mirror, a sandblasted type of surface, or something else. However, the mint typically takes special care with Proof (PF) coins as to careful handling and preparation. The striking procedure is modified to produce sharp edges and distinctive devices and usually were done "individually" or at least they weren't made by the thousands per minute and dumped into bins like the business strikes. The question is a little vague in that the type of proof can vary, so distinguishing between a 1909 VDB lincoln Matte Proof and a 1909 VDB Lincoln business strike is different than distinguishing between a 1936 Lincoln Business strike and a 1936 Lincoln Brilliant proof, or the 1936 Lincoln Satin proof ( 2 different types of proof for that year). In general the surface of the proof will have no bag marks or dings caused by other business strike coins falling on them. Hope this helps. Jim
Since 2005, there are actually two different kinds of "Mint" coins. Those that are produced for general circulation having no special surface treatment of the dies or special handling for bulk packaging and distribution are often referred to as business strikes. Mint state coins produced for the Uncirculated Mint Sets have a satin finish produced by bombarding the dies with a special combination of sand and glass beads. These coins are given special handling in production and packaging to minimize damage. Proof coins when placed alongside even the satin finish coins will stand out like a sore thumb. Both the dies and the planchets have been highly polished and the devices are given a frost-like surface to enhance the cameo effect. The fields will have very deep mirrors. Chris
very professionally answered! great info jim. thanks. you explained it very easily to understand and specific
I cannot add much to the wonderful posts already in this thread except to state that you should examine several proof and business strike coins in-hand and side-by-side so as to see the stark difference in "feel" between the two methods of manufacture. Once you do this you will be able to get a better idea as to which is which when you see them in the future.
Further, proof coins can be broken down into era categories, let’s just say that modern proof coinage started in 1968 when the proof operation was moved from the Mother Mint in Philadephia to the San Fransisco Mint. This year, 1968 was the beginning of all the coins in the proof set, half, quarter, dime, nickel and cent to come off the presses with consistent cameo surfaces. As the years progressed through the 70’ & 80’s the San Francisco Mint excelled at creating the Deep Cameo proof coins with the ultimate Ultra-Deep Cameo in the 90’s continuing through to this day. In 1968, the Cupro-nickel clad alloy proved to be a real challenge, but after careful annealing and polishing of the raw planchets, progress was being made. Now, combined with the extra tons per square inch during the pressing, plus the fact the coin is struck twice by the dies, bringing up and defining the devices and lettering, a proof (method of manufacture) is made. The actual coin dies were highly polished with the recesses (devices and lettering) are blasted with micron size beads which will impart a frosty appearance on the struck coin. The polished fields of the die will leave the surface of the coin super smooth and with a mirror like appearance. The coins are inspected as they are produced and the dies are removed at the slightest hint of degradation. The worn dies are refurbished and returned to service. This amount of quality control gives the collector the optimum coin to have in their collection. Some of the best examples of proof coinage from this era were the 90% silver dollars, halves, quarters & dimes…they are truly superb examples of what our mint was capable of producing. Note: When I first started surfing auction sites like e-Bay, sellers were always confusing “Mint Set” when they meant “Proof Set” and visa-versa. I still run across auctions where this occurs, either they don’t care, don’t know or are using key words to attract more attention, glad you want to learn the difference. Happy Collecting
Sometimes the average collector just can't tell. In my case I was after a proof 1941 "with AW" half dollar. Saw one slabbed PF-65 (PCGS or NGC) which would have been perfect for what I wanted. Sharpest "AW" of any I'd ever seen. BUT The coin had a very dull and somewhat uneven toning. And I believe the same dies were used to make both business and proof strikes. The Mint would just REALLY polish up the dies for striking proofs. That's how the "no AW" variety came to exist; got polished right off. So how did PCGS/NGC determine that it was proof? The dies are the same. I can only guess they looked "through" the toning and discerned the proof surfaces. I didn't buy the coin.
It is somewhat misleading to put so much emphasis on the surface. Yes in modern times, the enhancements in the minting process, and the demand for proof sets led the economically hampered treasury to start producing more sellable sets of coins they would not expect to be spent for goods ( Similar to the Post Office issues of the time). "Frost", MS-68+ surfaces, experimental surfaces were to entice the multitudes to buy the sets. Originally Proofs were to demonstrate the artistic and minting ability of the Mint, that is why matte, satin, brilliant, and other surface treatments were/are done. But the proof will also have special preparation of the dies, striking pressure, and even the number of strike blows to set the coin surface. The edges will be sharper, sometimes deeper, devices full, etc. This forum sees very often a person asking if they have a proof, almost always based on how "shiny" reflective it is. Often the replies are also based on the reflectivity of the surface. More emphasis should be on the characteristic of the strike. As was mentioned, sometimes in past, the mint either used proof quality planchets with business strike dies, or business strike planchets with proof dies, so the surface would not be a good indicator.
