If you will remember we left off with the information that the important information to be had from grading a coin was not whether or not it had sustained any damage, but whether or not that damage had occurred before, during or after it was struck. Since all damage to any metal consists of three basic types, incusion - the act of gouging or scraping the surface of the metal to the underlying layers - or embossment - the act of lowering the surrounding surfaces of the metal so that the area in question appears to stand over the surroundings - and heat - the act of melting the metal so that it flows or bends more easily - then it should be possible to systematically describe each of the potential damages that can and do occur to the surface of the coin in terms of one or the other of these kinds of damage. For instances, the tumbling that coin planchets go through in order to polish them to a high shine before striking is, in fact, hundreds of thousands of micoscopic incusions to the surface of the metal, each of which reflects the light that strikes it in a slightly different direction that spreads the shine out in a randon and even pattern throughout the surface of the coin and makes it appear to have a mirror like surfce, very relective.

On the other hand when a coin is struck with an incused die, which almost all are, then it embosses the surface of the coin with the incused device of the die and the device stands out as an embossed surface on the planchet.

The high pressure needed to strike a coin creates not only pressure, but high enough heat to melt the surface layers of the metal, which then flow outward from the center, highest area of pressure, towards the rims, lowest area of pressure. These microscopic metallic flow lines that are embossed in the surface of the metal are what cause "luster" and they are only a few molecules of metal thick and easily scraped off.

When they rub up against other coins, or slide across the surfaces of other objects the luster can be rubbed away, and may appear as areas in the luster that appear to be gone. Then there are areas in the luster where for one reason or another the metal never actually heated sufficiently to melt and flow, these generally tend to appear on the surface of the coin like worm shaped lines in the luster that may take random shapes and often give an uncirculated coin a characteristic, almost fingerprint like pattern of "luster fussiness" on the surface. Now, the difference between these kinds of marks, "slide" marks and "luster fussiness" is this. Slide marks are damage caused post-strike, while luster fussiness is caused at-strike.

Of course the sixty-four million dollar question is how to tell the differences between pre-, at-, and post-strike damage? First, get over the notion that you can tell the difference with the unaided eye or even a 5x magnifier. Certainly, there are a great many coins that one can jump right off the eye appeal to a grade that is wholly correct.

However, when a coin begins to present a paradox of some kind; it looks too good to be true, it looks bad but there doesn't appear to be any visible damage, etc., etc. The point here is that some coins look great when you see them unaided, but when looked at on the microscopic level they appear to present "problems". It is those problems that the real collector and investor must understand and be able to distinguish in order to fully understand the coin, its history, its experience in the marketplace and its real damage.

Our next guide will delve into the "problem" areas of coins, how some are not really problems and how some are enormous problems undetected...