It cannot be repeated enough how important it is for an authenticator to know what genuine coins look like in order to make correct determinations about the coins he or she is shown. Coins have dozens of attributes associated with their style, color, fabric, shape and execution, just to name a few. ?Mint quality? is the catch-all term we coined to take in all these characteristics as they appear on a genuine coin.
I?ve written about mint quality before in both grading and authentication columns. Nevertheless, let me explain the term again. It can be shown that coins made at the same place and during the same time period by an issuing authority will look similar to each other. They will possess the same mint quality.
The mint quality for each country and sometimes individual mints changed over time as coin making technology and skill was improved. Thus, the quality of the dies and planchets, the consistency of the alloy, the engraving skills, transfer technology and method of striking were generally refined and improved over time in a linear progression. We can trace this fact through the ages using ancient to modern coins. For this reason, although all genuine coins struck by the same country can be said to be of mint quality, those made in the 17th century will differ from that country?s 20th century coinage. In most cases, they just look different!
That is why the crown size coin from Chile that inspired this column caught my eye in the first place. This coin did not have the characteristic mint quality I should expect to find on a 19th century coin from Chile. As I reached over to see what it was, the first characteristic I noticed was its bright, reflective, proof-like surface. The coin looked to be in excellent condition until I saw a multitude of hairline scratches from some former cleaning or mishandling. Next, my eyes were drawn to the date and legend. They were more fat and rounded than I had expected to see. The letters and numerals on coins made in the 1800s generally are in sharp relief due to the way they were punched into the dies. My first impression was that I was looking at a possible counterfeit. Is it starting to make some sense? The experience gained from examining coins closely was raising my suspicion that something was not right here.
Let?s compare the prooflike 1883 unc. peso coin in Figure 1 (which turned out to be a restrike: KM-142.3) with an 1867 unc. peso (Figure 2). Can you see the difference in the lettering and feather detail? This ?look? marks the difference between a genuine coin with mint quality (for its time era and mint) and something else ? perhaps a genuine government restrike (in this case, made in 1926), a contemporary counterfeit, fantasy coin or a modern fake. I?ll bet that the dies for this coin were produced using a transfer lathe. That would explain the roundness of its design as compared to the older coin.
I should close this example with one note of caution. I used the 1867 coin to illustrate the same type of difference that an authenticator should expect to find on a genuine coin with mint quality for a specific country, mint and time period as compared with something (the 1883 restrike) that is not of the same mint quality. If this were an actual authentication case, I would need to find a comparison coin of 1883 or much closer to that date in order to be sure that the mint in Chile had not changed its style of letters over to the fat, rounded type seen on the coin in question.
You can add to your knowledge of genuine coins by examining them at museums, coin shows, with fellow collectors or at your local coin dealer?s shop. Remember to observe courtesy, wait for times the dealer is not busy and make an occasional purchase. Specialists may be more approachable and knowledgeable. They can explain mint quality and trace how it changes over time with hard examples from their case.