Analysis of the Roman aureus?

[Rosa S]

Hello to all members of this forum.
For twenty years dealing with gold, and have one of the biggest companies selling jewelry in Bulgaria.
We also have own Lab, in which we perform spectral and chemical analysis of precious metals.
From 7 years, colected Roman coins mostly third century because they are affordable and cover quite a wide range of rulers. Because Bulgaria is known as the country in which made many false coins, burn, as in the beginning, novice collector, with time and abilities I took to buy coins from reputable dealers and auction houses. I have a collection of over 170 denarius and almost as antoninianus. And 6 aureus from third century..So to get back to the topic of actually writing. And my 6 aureus who have been with certificates of authenticity. And all I've done spectral and chemical analysis, and none of them exceeds the purity of the gold over 97% ..They are mainly in the border of 96%, as one is even 94%..
I'm writing this post because I read a lot, and in the meantime, many doubt the Romans to have had technique as with us in modern times, to achieve this high purity of gold as described er "over 99%"..I think it is ridiculous to assert this view, and who had spoken so simply mislead others.
Thanks for taking the time to read this post !!
I'll be glad if someone can refute my opinion as an expert on precious metals and methods for their refining ..
Thank you
Best Regards
R.S


https://www.forumancientcoins.com/numiswiki/view.asp?key=aureus

[jmuona]

Dear R.S.
I think you - as well as others perhaps - do not understand the statement correctly. It is not ridiculous at all. These numbers refer to gold bullion. There were other metals inevitably, especially silver and copper. None of the resarchers think it was pure gold. Of course, naturally occuring pure gold exists, even though it is very rare, and thus such a Greek coin could exist. Mostly they are of a mixture of silver mainly, that is electrum. Roman coins were made of refined gold buillion to the limits they were able to purify it.
Jyrki Muona

[Joe Sermarini]

I have indeed read many times that Roman aurei are nearly pure gold and yes, over 99% pure.  If anyone else can confirm this is true or false, or has other examples of test results, please share.  

[Pekka K]

Butcher - Ponting p.6 note 5 points where this information is found.

Pekka K

[Jochen]

Howgego writes (in "Ancient History from Coins", p. 126): "It was under Aurelian [...] that the gold coinage returned to full purity." That implies that in the time before there was a lack of full purity of the gold coinage. I think it has begun under Severus Alexander.

Best regards

[SC]

The purity achieved depends on the techniques used, the amount of work put in (including, with some techniques, the number of times some steps are repeated), the composition of the original metal, and the skill of the workers.

There are several cases of pre-Roman gold items (European late bronze age; New Kingdom Egyptian) with purity levels of 99.9% and even 99.99%.  Google the Bernstorf gold finds for some further details of one example.  That these items are not the result of modern gold refining (i.e. modern forgeries) was determined by the presence of trace metals which would have been removed if any modern techniques were used.

Shawn

[Rosa S]

Hello
This is very good information from purity gold...

https://en.m.wikipedia.org/wiki/Fineness

Analyses gold roman aureus is 94-97 percent gold.

Best Regards

R.S.

[Rosa S]

Many say it exactly that with modern techniques, these metals disappeared from which gold becomes pure,but when these metals remain, there is no way to obtain a high purity gold ..
Best Regards
R.S.

[SC]

The 99.99% pure item I wrote about was European LBA - so roughly 1000 - 800 BC.  It still had minute traces of rarer elements that for some reason (higher heat ) disappear with modern technology and thus were deemed genuine ancient items.

Obviously few items had that level of purity but it demonstrates that there was, in effect, no absolute upper limit.  It varied by technique, effort and skill.

Shawn

[glebe]

The Bernstorf items are modern fakes according to Ernst Pernicka - see here, p. 517-524:

https://www.academia.edu/10493118

On the other hand Pernicka also points out that repeated refining by the cementation process can produce gold with only 0.001% silver and 0.01% copper (which surprised me - see his Fig. 3), and he refers to a dissertation giving figures of up to 99.8% for the purity of Roman gold coins (but doesn't specify which coins or periods are involved).

Ross G.

[Rosa S]

The Bernstorf items are modern fakes according to Ernst Pernicka - see here, p.517-524:

https://www.academia.edu/10493118

On the other hand Pernicka also points out that repeated refining by the cementation process can produce gold with only 0.001% silver and 0.01% copper (which surprised me - see his Fig. 3), and he refers to a dissertation giving figures of up to 99.8% for the purity of Roman gold coins (but doesn't specify which coins or periods are involved).

Ross G.

writes about Aureus of Trebonianus Gallus .. three different samples .. most low is 95.4% higher at 97.1%