# How the heck did they make this?



## METLMASHER (Mar 1, 2015)

As the title suggests, I would like to know how this purity was obtained. For thousands of years before the sinking of the Geldermalsen, where this ingot was recovered, there were ways to purify gold. I have fire... I still have no idea how to purify gold, silver, copper, mechanically. ( By fire. )

Is it a secret recipe? :roll: 

http://www.oceantreasures.org/pages/content/famous-wrecks/old-treasures-and-shipwreck-news-voc-geldermalsen.html

Ingot shown with cursor at 1 1/2 inches from bottom.

Also, as I know a bunch of you here have seen a lot more gold purified than I, any guesses as to purity?


----------



## Geo (Mar 1, 2015)

From wikipedia : 

Aqua regia first appeared in the work of the European alchemist Pseudo-Geber, dating from the early 14th century.[10] The third of Basil Valentine’s keys shows a dragon in the foreground and a rooster eating a fox eating a rooster in the background. The rooster symbolizes gold (from its association with sunrise and the sun’s association with gold), and the fox represents aqua regia. The repetitive dissolving, heating, and redissolving (the rooster eating the fox eating the rooster) leads to the buildup of chlorine gas in the flask. The gold then volatilizes in the form of gold chloride, whose red crystals were known as dragon’s blood. The reaction was not reported in modern chemical literature until 1890.

Aqua Regia (refining with acids) had been known for around three hundred years before the ship was built.


----------



## METLMASHER (Mar 2, 2015)

METLMASHER said:


> I have fire... I still have no idea how to purify gold, silver, copper, mechanically. ( By fire. )
> 
> any guesses as to purity?


----------



## Geo (Mar 2, 2015)

Gravity separation and smelting will give a doré bar. This is as close as you can get without acid. You may be able to purify a small amount with a cupel at a time but it would still be a mixed metal. 

Not sure what your driving at. There is no way to mechanically separate gold and silver once it has be alloyed together.

http://en.wikipedia.org/wiki/Gold_parting


----------



## nickvc (Mar 2, 2015)

Ancient civilisations used salt and heat to purify/ refine their gold a nod even today it's common to add copper to gold and then melt and dissolve of the base metals using nitric acid, of done correctly you will get 98% + purity.


----------



## g_axelsson (Mar 2, 2015)

I made a quick search in an etymological thesaurus and found a reference of separating gold from silver with nitric acid in a Swedish book from a 1534.

In 1556 Georgius Agricola published the book De re metallica and one chapter was spent on how to separate gold from silver. Both acid ways and smelting with stibnite is described, the stibnite turns the silver into silver sulfide and the antimony mixes in with the gold. the antimony and gold is separated by cupellation.
https://en.wikipedia.org/wiki/De_re_metallica#Book_X:_Separating_silver_from_gold_and_lead_from_gold_or_silver

Göran


----------



## METLMASHER (Mar 2, 2015)

Thank you everyone for the links, and help. I'd like more info for salt firing, but might not try it, if it sends out chlorine gas. I read everything there, but will continue searches here and other web sites for more detailed guidance.

Specifically the vessel the ancients used, was it glazed, and shape. I couldn't find any photos, but my skill there may be sub.

Any guesses of purity? I don't have any idea, but my guess is 99.7 gold. Could not find crystaline gold surface.


----------



## kurtak (Mar 3, 2015)

METLMASHER said:


> Any guesses of purity? I don't have any idea, but my guess is 99.7 gold. Could not find crystaline gold surface.



METLMASHER

According to wiki (the link Geo provided) the salt cementation process could go from 37.5% to 93% -------

"Salt cementation[edit]

This process was used from Lydian to post medieval times. It is a solid state process relying on common salt as the active ingredient but it is possible to use a mixture of saltpetre (KNO3) and green vitriol (FeSO4). The basic process involved the mixing of argentiferous gold foil (in later periods granules were used), common salt and brick dust or burnt clay in a closed and sealed container. Theophilus mentions the addition of urine to the mix. With heating, the silver reacts with the salt to form silver chloride which is removed leaving a purified gold behind. Conditions needed for this process are below 1000 °C as the gold should not melt. Silver can be recovered by smelting the debris.[15] Heating can take 24 hours. Hoover and Hoover[16] explains the process thus: under heating salt (sodium chloride, NaCl) decomposes in the presence of silica and alumina (from the brick dust or clay) to produce hydrochloric acid and also some chlorine. This reacts with the silver to produce silver chloride (AgCl). The urine is acidic and aids decomposition. Silver chloride is volatile and would be removed from the metal. And the container is sealed to stop the escape of the silver which can be recovered later. Notton in experiments found that with one heating the gold content could be taken from 37.5% to 93%

This is the process that goes back at least a few centuries BC - which means it is most likely the process talked about in the bible when they speak of the refiners fire & separating the dross to achieve pure gold ( looking at the bible from a purely historical view) 

The bible (at least to me) is quite the history book (if you look at it purely from that point of view) Much of the conflict over control of power & trade that took place back then is still taking place today --- the God twist part of the bible is a written "opinion" of man - but the conflict over control of power & trade is another story & the refinement of gold (& other metals) is part of that history - recorded in the bible

Kurt


----------



## METLMASHER (Mar 3, 2015)

Hi Kurtak, yes, I read the links provided, and links from there to other pages as well, great read! I think the salt cementation techn. is good for _recovery_, refining... not so much. The ingots do look higher than 93% to my untrained eye. :mrgreen: *nummy
*
The history in Bible is good for a comparator, even for the lay person. As for discussions further, let there be none in this thread. I have my beliefs, but they won't be written here. That in respect for this forum. 

Best.


----------

