Timeline Updates


In my book, Treasure Coins of the Nuestra Señora de Atocha and the Santa Margarita, time frames of assayer authority are presented as circa’s. The word “circa” means approximate or nearly, so while some years are confirmed, designations for coins produced prior to the addition of year of strike are in many cases estimates based on information culled by researchers from incomplete surviving records, as well as evolving artistic styles of coin die emblems, and assayer initial overstrikes and combinations. Therefore, our study of this data remains a work in progress, always subject to updating as new information is discovered in archival documents and through direct observation of the coins themselves.


Mexico Mint Edits:

With thanks to my friend and colleage, historic research expert Jorge Proctor, my forthcomiing (and long overdue) book, Pieces of Eight - Treasure Coins of the 1622 Shipwrecks Nuestra Señora de Atocha, Santa Margarita and the Portuguese Carrack São José, will reflect the following edits to the Mexico mint assayer attributions that appear in my current book:


1) Former attributions naming Francisco de Quintana Dueñas (circa 1598/1599) as assayer are to be disregarded. Proctor confirmed that while  Francisco de Quintana Dueñas did serve as treasurer of the mint, he did not serve as an assayer and is not the o/D assayer seen in conjunction with assayer F.

2) Bernardo Onate began his work at the Mexico mint before the currently listed 1564, probably around the mid-1550’s.

3) Known Mexico mint, S assayer coins do not appear to correspond to other coins of the time frame in which the formerly attributed official, one Rodrigo Gómez de Santillán, would have been responsible for assayer duties. Proctor credits Daniel Sedwick, author of The Practical Book of Cobs, for the updated information he provided, saying that it was through working directly with the coins of the circa 1550 "Golden Fleece" shipwreck and the 1554 Fleet Padre Island shipwrecks that Sedwick noticed and pointed out that, rather than the previously thought circa 1543/44, the coins of assayer S were more likely minted before or around 1554 (but no earlier than 1550) and therefore the issue of an assayer other than Gómez de Santillán. Readers can learn more about the Golden Fleece shipwrecks on the Education pages at sedwickcoins.com.


Potosi Mint Updates:

Again, thanks to the research of Jorge Proctor, there have been several very notable updates to the Potosi assayer timeline since my first book was published in 2010. I had searched for some years - in vain - to learn a specific year of death for Potosi assayer Baltasar Ramos Leceta. Multiple authors had him working in Potosi in 1618, but an essay by the late Kurt Dym, published in "The Coinage of El Peru" in 1988 - while not stating a specific year of death - did provide documentation that Ramos Leceta was deceased by the year 1616. This would have made it extremely difficult for him to have worked in the mint in 1618. Note that Jorge Proctor's recently published research identifies a 1612 year of death for assayer Baltasar Ramos Leceta. Thank you Jorge! Proctor's recently published research also confirms that the 1618 assayer monogram formerly attributed to Ramos Leceta belongs to Pedro Martín de Palencia, with his term beginning in late 1617 rather than 1618. Lastly, Proctor has identified the Philip III assayer M previously believed to have been Juan Munoz, as Juan Sanchez Mejia.


(Philip II era)

R – Alonso Rincon - c. 1574-1576

M c.1576-c.1577

B – Juan de Ballesteros Narváez - c.1577-1586 Alternately

L c.1577-c.1581 Alternately

C c.1577-c.1586 Alternately

A  - Juan Álvarez Reinaltes - 1586-1589

B – Juan de Ballesteros Narváez / Hernando Ballesteros -1589-1598 Alternately

RL; RBL – Baltasar Ramos Leceta - c.1590-1598 Alternately


(Philip III-IV era)

B - Juan de Ballesteros Narváez - 1598-c.1610 Alternately

R/B; RL; RBL - Baltasar Ramos Leceta - c.1598-c.1610 Alternately

R - Baltasar Ramos Leceta  - c.1610-1612 (large curved R)

C c.1612-c.1616

Q - Agustín de la Quadra - 1612-1616

M - Juan Sanchez Mejia -1616-1617

PAL - Pedro Martín de Palencia - 1617-1618

T - Juan Ximénez de Tapia - 1618-1648 Alternately

P - Pedro Martín de Palencia - 1622-1629 Alternately**


**Note that while Potosi assayer P coins have been documented on Florida's 1622 shipwrecks, I have spent a few years trying to substantiate that information. So far, the few coins documented as P assayer that I have found have been misattributions. I did, however, find a 1622 dated P assayer coin among those recovered from the 1631 shipwreck San Jose - so it is certain that P did assay Potosi coins in 1622, but the question remains whether he was doing so in time for any to have been part of (Florida's) 1622 Fleet cargo. ct