Saturday, March 22, 2014

3/22/14 - Bogota Mint Platinum In The 18th Century & Gold Religious Medallion Beach Find

Written by the TreasureGuide for the exclusive use of

14K Religious Medallion Find From The Treasure Coast
With the nice weather and the large number of tourists this year, there are a good number of modern jewelry items being lost and found on the swimming beaches even on the Treasure Coast.

Here is one new find.

It is easy to make a mistake by throwing something away before you really know enough about it.  I know because I made a number of mistakes like that in the past.  Unfortunately we often learn our lesson when it is too late.  We can keep learning though and cut down on the number of mistakes we make in the future. 

A few posts ago I showed some very small and very heavy lumps of metal that were detected on a wreck beach back a week or so ago when it was cut.  I know that a lot of people would quickly dismiss those small beads of material.  I can understand that, and the beads are probably not anything of interest, but due to the fact that I don't know exactly what they are yet, my curiosity is more than enough for me to hold onto them for a while.  I'll test them more thoroughly later. 

I haven't bothered to run many tests on them yet, partly because I'm out of some of my acids.  There is no harm in waiting anyhow.  I've learned that there is no harm in holding onto something that is probably nothing important.  If nothing else, the presence of items like that often leads to research and learning.  That has already been the case with these items even though they are most likely nothing very interesting. 
I ran across an interesting article last night that could possibly be remotely relevant.   It is an article published in Platinum Metals Review, 1992, 36, (I), 40-47, which discusses a manuscript written by an assayer at the Bogota mint dealing with platinum and its separation from gold and its refinement.

Here is the link to that article.

And here is the abstract of that article.

It is generally accepted that the first description of “platina” to appear in Europe was by a young Spanish naval officer, Antonio de Ulloa, whose famous work “Relacibn del Viaje a la America Meridional” was publishedin 1748. Important though this was, of even greater significance was the fact that the primary metallurgy of platinum must have been established much earlier, enabling it to be extracted, purified and manufactured. These processes appear to have been kept secret from
other European countries, and until recently their details had not been  deduced. Now manuscripts discovered in the Colombian Archives enable known methods of purification to be linked to the description of the primitive manufacturing process.

So it turns out that some of the earliest work, if not the first metallurgical work with platinum was conducted at the Casa de la Moneda de Santa Fe de Bogota.

Platinum for some time was thought to be little more than a waste product to be removed from gold, but later it was separated and used itself to construct items.

Jose Sanchez de la Torre y Armas was the assayer at the Bogota mint from January 1722 to 1732 and wrote extensively on the refinement and use of platinum.  It appears that much of what he wrote was known well before the time that he wrote it down.

More from the same article.

In the light of present knowledge, we consider that the platinum obtained by Sanchez would have been practically pure, although it is certain that his objective would have been the separation of platinum from the gold, rather than the refining of the platinum. Sanchez states that he produced calcined platinum and platinum grains, in which state the platinum could be readily hot-forged.

Notice the use of the word "grains."
 Assayer Sanchez wrote an explanation of a few says that platinum could be separated and the costs associated with the different methods.

Here is another paragraph from the article.

Of even greater importance is the fact that fabricated platinum articles existed in the first third of the Eighteenth Century, necessitating a refining or purification process and, in the absence of the means to melt it, a hot-pressing or sintering process that enabled the platinum to be worked subsequently.

So sometime in the first third of the 18th century, platinum that was mined with gold was separated and refined and actually used to manufacture things such as medallions, buckles, and even sword handles.

One last little interesting tidbit from the article.

The act of throwing the platinum into the rivers can easily be justified. The cost to the Spanish Crown of the introduction of just 5.4 per cent of platinum into the gold alloy would be the value of ...

Hmmmm.   Throwing platinum into the river!   

So what does all of that mean to us Treasure Coast detectorists.   One of the things that interested me is that items or parts of items were created from platinum early in the 18th Century.

Another thing is that when gold is less than 22k there could be platinum in it.  The heavy cost of removing the platinum provided enough incentive to overlook the "impurity."

And if gold nuggets were transported legally or illegally, is it possible that platinum in one form or another (including forms such as grains) was also intentionally or unintentionally transported with the ore.

Those are a just a few thoughts.  You might dismiss some or all of them quickly.

One thing I know is that the very small beads of heavy metal that I posted the other day will be tested more thoroughly because of what I learned in this article.  I still think they are more than likely lead, but am not ready to dismiss them without testing.

Lead or not, I learned something from the research and the remote possibility that the found beads could possibly be platinum rendered I read more interesting and meaningful to me.  And I learned a little more simply because they were on my mind and influenced my reading.

I did find it difficult to post from such a technical article.  It took a lot of time.  I hope you get something out of it.  I did.

I did a post on modern platinum items in my 6/6/13 post.  You might want to go back and read that.

On the Treasure Coast we now have a little bigger surf.  It is running around four feet and will not change much for several days.

I would expect to find some nice coin holes and modern gold other than recent drops out there during current conditions.

Happy hunting,