Buttrey condemned these as fake at the International Numismatic Congress in 1973 (Buttrey 1973). Buttrey pointed out that the lack of a mark of weight and the lack of a standard was an indication of falsity. Walter Breen later proposed a criterion to test for genuineness: if the bars were equal to the Spanish marco (230.04 grams) or a fraction thereof, they would pass a first test for genuineness. If they were struck to no standard at all, they would be false. None of the bars has a weight even close to 230.04 or a whole fraction or multiple of it. So under Breen's criterion, the bars are false (Breen 1979?).
The cataloguer for Stack's Gibson sale drew on this research into Spanish weights, but could not argue that the bars were struck to the weight of the marco, for they are not (Stack's 11/1974:271). By a lucky chance one bar weighed 169.053 grams, and this bar was auctioned in the Gibson sale. Since the escudo weighs 3.383 grams, this makes the bar worth very close to 50 escudos. However, an analysis of twenty-four bars with published weights (Buttrey 1973, 36) show that nearly all of them are struck to neither of these standards - neither the escudo standard nor the marco standard.
The Gibson sale cataloguer suggested a criterion for genuineness of the bars: if the bars were struck close to fractions or multiples of 50 escudos, the bars were genuine. But only one bar chanced upon that weight - lot 271 of the Gibson sale. Since none of the rest meet the 50 escudos standard, using the criterion proposed by the Gibson sale cataloguer, the bars are false.
B. The Presence of Aluminum in the Mexican Gold Bars Indicates that they are Fake.
Wolfgang Fischer-Bossert has proposed another criterion that proves that the Mexican gold bars are fake: the presence of aluminum as a trace element, as shown by E. G. V. Newman's tests of the bars. Pure aluminum was not generally available until the invention of the Hall-Héroult process in 1886; yet these bars, ostensibly of eighteenth century manufacture, contain aluminum. This argument needs to be confirmed by the accumulation of more comparative evidence, but an examination of the series Metallurgy in Numismatics (all studies of pre-1850 objects) turned up no pieces that tested positive for aluminum as one of the trace elements. This provides yet more evidence that the Mexican gold bars are false (Fischer-Bossert 2001).
C. Further evidence that the Mexican bars are false and Hodder's attempt at refutation.
Buttrey's argument against the Mexican gold bars was by no means confined to the lack of weight standard. Particularly damning was the use of a coin die that could be dated to 1770-71 - on a bar that was stamped “1744.” The forger, in making bars that were ostensibly from the 1740s, had used a coin die from twenty-six years later (Buttrey 1973, 39).
In 1990, E. G. V. Newman carried out non-destructive testing of the Mexican gold bars. Newman found the trace elements to be far too low for Spanish gold of the eighteenth century (Newman 1990). Hodder tried to refute this in a letter, citing tests run at the Boston Museum of Fine Arts in 1975 (Hodder 1990). However, Hodder used figures from equipment that had not been set up to test for trace elements, so his arguments were irrelevant at best. Moreover, the results he cites are so bizarre that we must reject them, for the Boston tests found the Mexican 8 escudos of the 1740s to be 880, 895, and 912 fine. The proper fineness of a Mexican 8 escudo of the 1740s is 916 2/3 fine.
Buttrey's work on the Mexican gold bars has been praised by others (Holabird 1999, DeLorey 1999). It was not until a quarter century had passed that a public attempt was made to refute Buttrey. This was by Hodder in his 1999 article about Western Gold Bars. Hodder patched together a series of arguments that are extraneous to the matter at hand, such as that the confusion in the mines at Potosí (now in Bolivia) indicates that there was confusion in the Spanish colonial mint at México, which explains the erratic shapes of the bars (Hodder 1999, 141-42). This is incorrect. Anyone who has studied the products of the mint of México from 1732 onwards would agree that in the eighteenth century, México was the best-run mint in the world. It produced more silver than anyone else, to a regular, reliable standard.
The chief argument that Hodder put forward for the authenticity of the Mexican bars was a pair of candlesticks, which bore a columnario type silversmith's stamp, even though dated 1729. Hodder made the far-fetched argument that this anachronism on a pair of silver candlesticks excuses any anachronisms on the Mexican gold bars. Weak though this argument is, it loses every shred of support when we go back and consult the source that Hodder cites (Boylan 1974). Hodder writes of the candlesticks that their “authenticity has never been questioned” and further “if these candlesticks are accepted as genuine, and there is no reason not to...” (Hodder 1999, 139). Although Boylan asserts that the candlesticks are genuine, her arguments are weak, based on nebulous ideas of style and connoisseurship. A careful examination of the stamps shows that they are identical to those used by the forger Apolonio Guevara in Mexico City in the 1930s. The leading authority on Mexican colonial silver, Anderson, identified Guevara's forgeries. Boylan's account of these candlesticks is a doughty but ultimately doomed attempt to uphold their genuineness; at least, however, she mentions Anderson's condemnation of the columnario punch as a forgery (Boylan 1974, 28-30). No such doubts come through in Hodder's account, however, who quietly omitted the anguished debate over the genuineness of these pieces and assures the reader that there is “no reason” to doubt the authenticity of the candlesticks.
Although Hodder quotes Breen's rhetoric (Hodder 1999, 99, 113-14), nowhere does he confront the problem that Breen found: the bars are not struck to any discernible weight standard, and certainly not to the marco standard. Under the Breen criterion, the bars are false. Hodder refuses to discuss this.
Recently, Professor Alan K. Craig and Ernest J. Richards, Jr., have published a pioneering study of Mexican colonial gold, silver, and copper bars. One of their chapters is devoted to forgeries - including the Mexican gold bars that Buttrey condemned in 1973. Although they are unaware of Buttrey's 1973 study, their conclusions are just as trenchant: these forgeries are “outrageous,” “They are the product of corrupt people with criminal intent” (Craig and Richards 2003, 148-51). We can only endorse their conclusions.
D. The false stories surrounding the origins of the Mexican bars.
A peculiar aspect of the Mexican bars' history - and one that adds to the strength of the argument against them - is that the story of their discovery keeps on changing. John Ford first said that the hoard of Mexican gold bars was discovered when a document was found in a Mexico City bookstore in 1951, which duplicated a document in the Archive of the Indies (Buttrey 1973, 28-29). In a 1979 letter, however, Ford changed his tune: there are no documents whatsoever (Ford 1979). Hodder repeats this later version (Hodder 1999, 138).
In the first version, John Ford acquires the bars through intermediaries of the finders in 1955-56 (Buttrey 1973, 28-29). In the second version, Ford does not appear at all, and the bars are sold to various dealers and collectors - F. C. C. Boyd, Stack's, Wayte Raymond (Stack's 11/1974, p. 84). In the third version Ford first encounters the bars in the F. C. C. Boyd Estate. F. C. C. Boyd died in 1958 - so this chronology does not tally with the early version (Van Winkle 1990, Part II, 22). And in the fourth version Ford buys the bars from Paul Franklin (New York Times, 3 March 2001, page B11). This last version tallies with the very first publication of these bars: when Paul Franklin exhibited a Mexican gold bar of 1746 at the Brooklyn Coin Club on September 1, 1954 (Numismatist 1954, 1214). But that chronology does not tally with version three.
The wreck is also mobile. First it is on the west coast of Florida - the ship had not yet left the Caribbean. Then it shifts over to the east and the Atlantic. Then, in the New York Times story, the story changes halfway through - it is from the east coast of Florida, but the man who had the bars did not really want to say, and he lived on one of the Florida Keys.
In 1974 the Gibson catalog said “the finders are unknown.” But in 2001 Ford knew that one of them lived on one of the Florida Keys.
There is yet another version - for contrary to the assertion in the Gibson sale, the “finders” have not chosen to remain unknown. Lieutenant Harry E. Rieseberg in 1962 published photographs of the Mexican gold bars, with the caption, “Relics and real treasure the author has salvaged from Gulf Waters. Gold ingots bear the Spanish mintmark ‘HISP & ID’- Hispaniola and the Indies” (Rieseberg 1962, plates II and III). One plate shows the bars and alleged Indian artifacts - figurines that look like gold gingerbread men - the other the bars and salvaged coins. So here is a third story, as opposed to “The finders are unknown” (Gibson sale) and “We don't know who the finder was, but he lived on the Keys:” “I, Lieutenant Harry Rieseberg, found the Mexican gold bars.” Note also that Rieseberg places this mobile wreck in the Gulf of Mexico.
The wreck has also changed its date. First it was in the 1740s. Buttrey showed that this was impossible, because the bars bore markings that were only possible in 1770-71. So in the March 2001 New York Times interview Ford said the wreck dated to the late 1780s. But this takes the bars out of the frying pan and puts them straight in the fire. For Spain reduced its gold standard twice: at the end of 1771 and in 1786. The gold fineness fell from 916 2/3 to 895. A wreck of the late 1780s should not bear bars with official marks struck to the standard of the 1740s. Matters do not improve if one were to argue that the “revalidation” marks are from the 1750s - or from 1770, because the fineness of the gold coinage dropped twice after those dates.
Which one of these stories is true? None is. They are all false, like the bars themselves.