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About book updates and corrections:

While I make every effort to present the most accurate and up-to-date information available in my books and papers, nonetheless it's always possible that an error will creep in, a reader will have information undiscovered by the author, or an archival research expert will make a blockbuster discovery the day after a thousand books go to print. The purpose of this page is to share updates and corrections so that you can make note of them in your personal copies.

Treasure Coins of the Nuestra Señora de Atocha & the Santa Margarita

The First Edition of Treasure Coins of the Nuestra Señora de Atocha & the Santa Margarita was released in 2010. The assayer/mint timeline information was based on the most up-to-date information available at that time; it included a list of source material but did not include specific bibliographical citations.


In late September of 2022 my Atocha/Margarita Second Edition was released, with assayer/mint timeline tables that reflect significant advances and updates, and which include bibliographical citations. This was followed in December of 2022 with a Third Edition, which includes a cosmetic change to the caption formatting, along with the following two corrections, and page 19 edit:

On page 51 of the Second Edition, the assayer initial displayed on the early Seville coin shown on page 51 was incorrectly described as P, but is in fact assayer initial F.


On page 33 of the Second Edition, the transition from “pillars without waves” dies to the “pillars with waves” type was incorrectly placed in the timeline table. The correction is shown here:

Lastly, after some discussion with my treasured colleague, historic research expert/numismatist Jorge Proctor, we agreed that there is a general need in numismatic publications for a definitive continuity in how mint and assayer marks are described. These conversations resulted in some new text, which was added in the Third Edition on page 19, and is thereafter reflected in any applicable captions:

Added to page 19:

"While most assayer marks consist of a single initial, some are monograms, and others are expressed with one initial above another, as is the case on Lima mint coins struck with a small “o” above “D,” representing the first and last letters of the name “Diego” (de la Torre), read from the bottom-up, as was the tradition.


In the same vein, some minting houses used more than one initial to render their mintmarks. For example, most shield-type Mexico City mint coins display a small “o” above “M,” representing the first and last letters of “Mexico,” read from the bottom-up. Other examples include Panama City coins, with the letter “A” above the letter “P,” and Nuevo Reino de Granada coins, which display “R” above “N.”


Hereafter in this publication, a backslash symbol is used to indicate assayer initial overstrikes, such as the example shown on this page, L/B = L over B. In cases where stacked initials, one above another, were used on coins to indicate mint of origin or assayer identity, these will be expressed sequentially, like so: Mo for Mexico City, PA for Panama City, Do for Diego de la Torre, etc."

Potosi mint, 4 reales, with assayer initial "L" struck on top of previous initial "B" (L/B).

Mexico City mint, 2 reales, with mintmark rendered as "o" above "M" (Mo).

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