Saturday, July 11, 2015

7/11/15 Report - Colonial Silver- Potosi (Bolivia) and Guanajuato (Mexico). History of Metals In The Colonies.

Written by the TreasureGuide for the exclusive use of

Ancient Silver
Refining Technique

Source: see lecture link below.

If you are interested in Potosi cobs or other South American silver objects, you'll like this.  It shows where the silver that you find on the Treasure Coast came from.

The source is a lecture from the University of Texas on silver.  The title is Colonial Silver- Potosi (Bolivia) and Guanajuato (Mexico).  It tells about everything related to silver, but really has a lot of information about Potosi, the geology, early mining and refining techniques, etc, as well as Guanajuato.  I think anyone interested in Spanish colonial silver will find this information fascinating.

Below is one slide with some great trivia about Potosi.

In 1572 Potosi had more inhabitants than London, Paris or Madrid.  Who would have thought?

And below is a cool slide from the same lecture showing how the Incas smelted silver.

Take a look.  Here is the link.


Sterling silver is 925 parts silver to 75 parts copper, thus 92.5% silver. 

Some countries use other standards for silver. Here are a few.
  • .950 – Japan, France
  • .925 – US, UK, Australia, Mexico
  • .900 – all early American silver is .900 or “coin silver”. Even Paul Revere’s work is not “sterling”
  • .875 – Soviet Union and the Baltic States
  • .830 – Scandinavian countries
  • .800 – Germany and France

You might also find this book interesting.  History of Metals In Colonial America, by James Mulholland, 1981.

This book concerns the colonies and does not address Spanish Florida.  Still, very interesting.

You can view a substantial sample of the book free online.  There is a lot of interest reading in that book.  It covers iron, copper, silver, etc.

This book explains how silver coins were melted and made into other objects such as silverware.  Those silver objects were marked and more easily identified if stolen.  And if and when cash was needed the silver could be easily converted again.

You'll find a lot of interested facts about metals in the early days of the colonies.

Click above to read the free sample sections of that book.


When I had an injury C Man sent me an email telling me about a detector harness.  He got one for his wife.  If your arm gets tired when detecting, you might think about getting one.

Here is a YouTube video C Man sent me showing the harness in use.

I actually have one that came with a detector that I bought, but haven't tried it out yet.


Still nothing more than a two foot surf predicted for the Treasure Coast for several days.  Beach hunters will be hunting mostly modern items, and there are a few of them out there due to the hot weather and the vacation time of year.

Happy hunting,