Assayers of the Mexico City mint during the Columnario (pillar) coinage (1732-1771)

by Jorge A. Proctor

There is great confusion when it comes to the identity of many of the working assayers of the Mint of Mexico between 1732 and 1821. While some of the names currently being published are correct, others, such as Felipe de Rivas Angulo, Manuel de la Peña, Francisco de Rivera, Manuel de Rivera and Joaquín Dávila Madrid, are not. Furthermore, two of the officials who worked during different periods had similar names. This has caused some scholars to misidentify them as one official who worked during two different periods. These are just a few of the errors that are often encountered today in catalogs, reference books, and other publications. In an attempt to finally bring some clarity to this subject and to provide the most accurate list possible, I offer this revision based on documents, mostly from the Archivo General de la Nación in Mexico, and confirmed by the coins themselves (special thanks go to John Pullin, who graciously provided me with images of coins from his collection). The revised assayer list, presented here, is the result of my research.

About the List

Each assayer mark (one or two letters) is paired with the name or names of the assayers who worked the post. Since the tenure of a working assayer would have begun the moment that the previous assayer died or was no longer in office, the initial year cited in the tenure is the year when the official would have started as a working assayer to maintain a steady coin production. This is not necessarily the year when his assayer mark (or the combined assayer marks) first appeared on the coins. For this reason, and to assist numismatists, the year when the new combined assayer marks are first seen on the coins is provided. As for the end of the tenure, I document the year when a change occurred, either when a new assayer is added, when one of the two working assayers is known to have died, or when one of the two working assayers is no longer in office. I also provide information on whether the previous assayer mark continued being used for the remainder of the year when the change occurred. Once the new combined assayer marks are introduced, what can be considered a transitional period is also documented, which covers the year or years when the new and old combined assayer marks are used concurrently, until when the change becomes finalized and the older marks are no longer used.

Initial(s)	Name(s)	Began on	Left office on
F	Francisco de la Peña y Flores	1732^{Francisco de la Peña y Flores’ tenure as working assayer started in 1730.}	1733
MF	Manuel de León Francisco de la Peña y Flores	1733	1754^{Archivo General de la Nación (AGN): Instituciones Coloniales, Gobierno Virreinal, Reales Cédulas Originales y Duplicados (100), Reales Cédulas Originales, Vol. 234, fs. 2. This document, from 18 October 1755 confirms the approval of Manuel de Asorín as the new working assayer of the mint due to the death of Francisco de la Peña y Flores, who had died in 1754. Manuel de Asorín had already started working in place of Francisco de la Peña y Flores sometime in 1754, as the coins confirm.}
MF started being used in 1733. Transitional period when MF and MM were used concurrently: 1754 only.
MM	Manuel de León Manuel de Asorín	1754	1762^{AGN: Instituciones Coloniales, Real Hacienda, Casa de Moneda (021), Vol. 186, Exp. 17, fs. 408. (1762) Report from María Gómez regarding the death of her husband, Manuel de Asorín, assayer of the Mint of Mexico. AGN: Instituciones Coloniales, Real Hacienda, Casa de Moneda (021), Vol. 326, Exp. 3, fs. 48-50. (1762) Order from the Superintendent of the Mint of Mexico to the diesinker, instructing him to include the letter F for assayer Francisco Antonio de la Peña y Flores on all the new dies that he was to make for the gold and silver coinage.}
MM started being used in 1754. Transitional period when MM and MF were used concurrently: 1762-65.^{A 1765/4 MM 8 Escudos in About Uncirculated condition was sold by Aureo & Calicó S. L., Sale #242, March 2012, Lot. 209.}
MF	Manuel de León Francisco Antonio de la Peña y Flores	1762	1769^{AGN: Instituciones Coloniales, Real Hacienda, Casa de Moneda (021), Vol. 45, Exp. 24, fs. 80. On 1 December 1769 Manuel de la Iglesia is assigned as a working assayer of the mint in place of Manuel de León who has just died. AGN: Instituciones Coloniales, Gobierno Virreinal, Correspondencia de Virreyes (036), Vol. 13, fs. 250. On 22 December 1769 a testimony of appointment of Manuel de la Iglesia, assayer in replacement of Manuel de León due to his death, is sent from the Viceroy of New Spain, Carlos Francisco de Croix, Marques of Croix, to Fray Don Julian de Arriaga, Minister of the Indies.}
MF started being used in 1762 . MF continued through 1769. Transitional period when MF and FM were used concurrently: 1770 only.
FM	Francisco Antonio de la Peña y Flores Manuel de la Iglesia	1769	1777^{The 1772 portrait silver coinage from Mexico (first Mexican dated coinage with the portrait design) carried an inverted mintmark and inverted assayer marks. Additionally, it has also been observed that some of the 1772 8 Reales also have the inverted assayer marks transposed as MF, rather than FM. The error of the inverted mintmark and assayer marks on the silver coinage is also observed on some of the silver coins from 1773.}
FM started being used in 1770.^{AGN: Instituciones Coloniales, Real Hacienda, Casa de Moneda (021), Vol. 133, Exp. 5, fs. 37-43v. (1777) Report of the salary paid to assayer Manuel de la Iglesia until the moment of his death.} Transitional period when FM and FF were used concurrently: 1777-78.^{A 1778 FM 8 Reales in Very Fine + condition was sold by Aureo & Calicó S. L., Sale #263, 29 October 2014, Lot. 469. Another specimen in Fine/Very Fine condition was sold by Martí Hervera & Soler y Llach, Sale #81, 15 May 2014, Lot. 90.}