(803) Untold Stories: Volume 2 Issue 8: Last Revision: 05/25/07
However, there were other early collectors such as the Virgil Brand, the Norwebs, Dr Pradeau, and a host of others who didn’t participate in this cleaning program. These astute collectors could and did appreciate the toning that comes over the years found on copper, silver and to a lesser degree gold coins. This is one of the reasons, we at Mexican Coin Magic; believe it is important to preserve the pedigree of all Mexican coins today.
Sometimes the early collectors cleaned their coins with care, but many others weren’t so careful. Today we sometimes find beautiful Uncirculated Mexican coins with harsh cleaning lines, from the use of abrasives, that makes one almost want to cry. Other times we find high-grade (Extra Fine) coins that have been “whizzed” or purposely polished on a buffing wheel. All of this was done just to have bright and shinny coins.
Thank goodness this practice is no longer popular with collectors in the USA or Mexico!
High-grade lusterless coins are a good indicator that the coin has been cleaned in the past. If a lower grade (Very Fine or slightly better) Mexican Republic coin has unbroken luster across its entire surface, it has probably been harshly cleaned, so look for tiny hairlines with a 10x magnifying glass because this is an unnatural occurrence.
The luster found on different Mexican Republic denominations from different mints can look totally different. For instance Mint State 8 Reales from San Luis Potosi generally have very subdued luster until late in the series, while those from Mexico City have bright cartwheel luster, and some from Oaxaca have a frosty luster that is very spectacular when found. Sometimes the overall luster is so wonderful it gives the individual coin the appearance of being a “Proof” coin. But don’t be fooled; there are no true Mexican “Proofs” until the early 20th Century.
A Norweb Coin Envelope
A Norweb Coin Envelope
Copper and Brass Reales & Centavos: Most minor reales and centavos not made of silver, struck during the Republic Period, were primarily made of copper. However, like everything else in Mexican Numismatics there are exceptions to this rule. The other material used for some minor reales was a brass alloy of .640 copper and .360 zinc. There are over 50 styles of minor (1/16, 1/8, and ¼) reales created by the Federal and State Governments, plus an almost uncountable number of tokens that were used for small change and to purchase items at the company stores run by haciendas. First, it is more than difficult to find these base-metal coins in grades higher than Fine. And when this happens most examples have been either harshly cleaned or dipped at some time or another because of corrosion problems. Therefore we will not spend a lot of time discussing them in this article because it is beyond the scope of this article. Most of the following discussion also applies to these copper and brass coins such as hairlines, etc. Just remember, if you don’t want cleaned coins in your collection, buyers beware. It is almost impossible to find Mexican Republic copper coins with any remaining “RED” unless they were and are still lacquered.
Silver Reales, Pesos & Centavos: The alloy used for most Mexican silver coins is .9027 silver and .0973 copper. This alloy used for Mexico’s silver coinage is very susceptible to tarnishing or oxidizing. Coin collectors generally call this oxidizing toning. Toning or oxidizing is caused when the upper most layer of silver on a coin is subjected to some outside substance (usually some form of sulfur) that causes a chemical reaction to this layer of silver and copper. Sometimes this oxidation assumes a light brown or chocolate color. Other times this toning can be blue, purple or a beautiful light rose. The worse cases of oxidation are when a silver coin starts to turn black. Generally if you find a silver Mexican coin over 100 years old without any toning … beware. It is highly unusual for any silver coin to survive this long without any toning. However there are a few cases where large hoards of Mexican silver coins have been found that were stored in mint bags where the coins in the middle of the bags have no toning and are bright white. But in these same bags the coins closest to the bag are generally toned in multi hued colors. Coins that were stored in paper rolls will generally have toning around the edges, while the centers of the coins inside the rolls may be bright white. Personally I’m always suspicious of non-hoard date Republican 8 Reales that are bright white with little or no cartwheel effect?
A Bright White Hoard Date 8 Reales
ex Norweb Toned 8 Reales
If toning is natural it will generally not be even across the entire surface of the coin on both sides. Therefore if the toning is completely even on both sides of the coin I believe the coin has generally been cleaned or dipped, and then placed in some artificial environment to be retoned. Different outside conditions can greatly effect the toning of Mexican silver coins. Let me give you one recent event where a hoard of Oaxaca 8 Reales sorta proves this.
Somewhere in Mexico a hoard, I call it the Millennium Hoard, of Oaxaca 8 Reales was found near the end of the 20th Century. All of the coins I personally saw from this hoard were Mint State or near Mint State examples. A few of the coins were bright white (with typical weak strikes, many had adjustment marks, or other problems) while all of the others had varying shades of toning. I don’t have any idea how many coins were in the hoard, but from their overall appearance I believe they were stored in a bag or bags. Some of the coins had toning on one side only, others had toning on both sides but the toning wasn’t the same on both sides. Many new varieties were found in this group that were previously unseen by collectors before the hoard, but all of the coins had very little, if any, wear that I saw personally or by way of pictures or scans. Therefore there are a few new bright white Oaxaca 8 Reales out in the market place that are natural, the dates for these coins ranged from 1858 until at least 1864. However they are the exception to the rule. Below are two different coins from this hoard, both have highly reflective luster that does not show up on the reproductions. Again a problem with all scanning techniques I've found so far.
A Millennium Hoard 1860 Oaxaca 8 Reales
A Millennium Hoard 1859 Oaxaca 8 Reales
Many times, after a number of years, a cleaned silver coin will begin to retone. But if you closely examine the coin with a 10x glass you will see signs of the cleaning hairlines under the toning. This is especially true if the coin has been polished or whizzed. All Extra Fine or higher-grade coins should have some underlying mint luster on them even if only in the low areas of the devises (the legends, in between the Eagle’s wings, in the wreaths, etc,). Therefore if a silver coin has what appears to be a matte-finish all the way across the surfaces, it has been harshly cleaned and is retoning, either naturally or artificially. (The only matte-finish Mexican coins I’m personally aware of are a few Caballito or “Horse Pesos” until modern times.)
Gold Escudos & Pesos: The alloy used for most gold coins from Mexico is .875 gold and .125 copper. While much less susceptible to oxidizing, Mexico’s gold coins will sometimes have a tiny amount of toning due to the copper content that is sometimes referred to as an “orange peel” effect. This old “orange peel” is very attractive, when it occurs, and generally insures that that the surfaces on that particular coin are original. Sometimes you will find references to “green” or “bright orange” colored gold Mexican coins in some old catalogs. Certain mines located in different parts of Mexico produced different colored gold that is noticeable, this is a natural occurrence because of the trace elements in the ore, so don’t be alarmed when you run across a “greenish tinged” escudo.
The gold alloy used for Mexican coins will sometimes show copper spots on the coin’s surface. These copper spots are usually round or oblong in shape and are the results of the metal melt not being complete. While this may be distracting to some collectors it is a natural occurring mint irregularity and sometimes can’t be helped. If I’m offered a coin with copper spots I always ask myself; what are the chances of finding this coin in this grade without the spots? If I believe one will come along I may pass up the coin. However, if I don’t think that is the case, I will plunk down my money in a heartbeat, copper spots be damned.
The first thing you should do is rotate the coin you are observing so the light source is at an oblique angle. If the coin you are studying is not a Mint State example you should notice some discernable differences in the coin’s surface, even if the wear is even. All circulated coins should have a few marks on the coin. Sometimes handling will cause the marks during circulation. At other times these marks are created when a coin was processed during minting. Remember there were no true “Proof” coins produced in any Mexican State mints and it was the early 20th Century before any were produced in the Mexico City Mint. Therefore completely clean surfaces on any Mexican Republic coin should raise a great big “red flag” for the collector indicating the subject coin has been “screwed” with. This said, there are a few “specimen” and “trial” strikes that I’ve seen in Mint State that have almost clean surfaces, but they are the exception to the rule.
Even the very best Mint State Mexican Colonial or Republic coins generally have a few light “bagmarks”. These are tiny marks in the fields, or on the high places of the coin, or tiny rim bumps or nicks caused when the coins in a bag contacted one another. Therefore any coin with totally clean surfaces and rims is questionable!
A Whizzed Mexico City 1887 25 Centavos
But all “hairlines” found on Mexican coins are not the result of cleaning a coin after it was manufactured. Sometimes we find “hairlines” on Mexican coins that are the result of cleaning or die polishing “hairlines” before the coin was struck. However, there is a difference in these two types of “hairlines”. And it takes good light and a 10x magnifying glass to tell the difference.
Coin cleaning “hairlines” dig into the surface of the coin. Die polishing “hairlines” are tiny raised lines found on the coin. Coin cleaning “hairlines” are bad. Die polishing “hairlines” are good. In order to tell one from the other you need that 10x glass and good light. Turn the coin so your light source is at an oblique angle; now look at the “hairlines”. Are they below the surface of the coin? If so they are bad. If the “hairlines” are raised (look for tiny shadows) they are good.
Die Polished "Good" Hairlined Durango 8 Escudo Pattern
When harshly cleaned coins start to retone novice collectors sometimes over look them. Always look at suspect coins under a 10x glass. You have to learn to look at these coins differently.
Think about it like looking at a storefront plate glass window. If you take a shallow look you will see your body reflected in the glass. If you look deeply into the glass window you will see the merchandise displayed for you to buy. Therefore you have to learn to look through the coin’s toning and look at the surfaces of the coin, not the toning. Are there “hairlines” under the toning? If so, are they good or bad hairlines? It’s easy once you get the hang of it, but it does take some practice to know the difference.
A Lightly Polished Zacatecas 1869 8 Escudo
With the early Republican gold (escudos) coins-- I’m more interested in the quality of the strike and the overall eye appeal than I am whether or not the coin has been cleaned. It is almost impossible to find rarer Mexican gold that hasn’t been cleaned at one time or another. Of course, just like all the different series of Mexican coins, there are hoard dates of Mexican gold where you can find pristine specimens for most simple Type Collections. However even some of the most common DAMs are more than difficult to find in Choice Uncirculated condition.
A Pristine Oaxaca 1861 8 Escudo
If you encounter a coin that you believe may have been cleaned there are several things to look for and think about before buying the coin.
Does the coin have distracting deep cleaning hairlines?
Does the coin still have “good” eye appeal-- strong strike, few if any mint flaws, etc?
Does the coin’s grade fit your collecting criteria?
What are your chances of ever buying a higher-grade coin?
How rare is the coin, will you ever find one that hasn’t been cleaned?
After you have examined the coin, and considered these questions make your choice: Buy it or pass it up.
Buying a cleaned coin is not the end of the world in Mexican Numismatics; most advanced collectors own at least a few. If you positively need a coin for your collection and it has been cleaned … buy it. But keep a few things in mind:
Cleaned coins are generally worth less than non-cleaned coins.
Always try to up grade a cleaned coin with one of a better grade that hasn’t been cleaned.
Buying a cleaned Mexican coin doesn’t make you an idiot or fool; we all have some cleaned coins in our collections that can never be up graded.
And last, but not least, if you can’t tell a coin has been cleaned then don’t worry about it.
Author’s Notes: (1) There is a very interesting book that all serious coin collectors need for their reference library about cleaning and maintaining their coins. This book is primarily about US Carson City Silver coins, but I’m sure you will find it interesting if you collect any silver coins. My copy is the 2nd Edition and is titled Coin Chemistry Including Preservation and Cleaning by Weimar W. White and it can generally be found in most coin shops. (2) You will have to excuse the quality of the coin reproductions in this article because all of the coins pictured here are scans and not high-quality photographs. My scanning quality is slowly improving over time, but as we have stated before; high definition scanning is fine for showing coins, their imperfections, different styles, and the various varieties, but it doesn't work well for displaying the true color or luster found on individual specimens.