Tinned Coins

So far, I've seen and heard of silvered ancient coins. These were plated officially with silver for some reason. But some while ago, I noticed by coincidence while looking for a coin on Wildwinds that my coin was listed or described as " Tinned ". That means plated with tin. That was my first encounter in this magic hobby which has no end or limits just like a witch.Ha.. The coin is of Aurelian with Sol on reverse (ORIENS). It was struck in Rome. RIC 62- V. Please post your tinned coins. Hope some fellow can shed light herein.

 

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Nice "tinned" coin. Not sure if my Aurelian was "tinned" rather than silvered, but here it is.

 

I don't think modern scholars believe coins were "tinned." Many chemical tests have proven there was "surface silvering." Tin was mined in England and is whitish so it came to the minds of English scholars over 100 years ago before surface compositions were known. If you read about "tinned" Roman coins I think it must be a legacy of an outdated theory. I suppose someone might have "tinned" a coin unofficially, but it was not a Roman mint practice.

 

There are still some dealers who use the word tinned for silvered.

 

Yes, but then again most ancients catalogs and the bulk of ancient coin books were published 50 or 60 years ago. There isn't exactly a plethora of new material around, so I can understand why some old notions persist.

Heck, have you noticed the tons of coins on Vcoins being sold at exorbitant prices because they are "unpublished"? Who would have thought that in a pre-internet, pre-globalization era where the world was divided by a Cold War that these catalog compilers missed publishing coins that today we know about and are not super rare, and many of those that were published and deemed "rare" we now know to be a lot more common, especially after the fall of the Eastern block. What I'm getting at is that these catalogs and sources we rely on, many of them are somewhat outdated by now and in bad need of modern revisions. If you rely eclusively on these catalogs and old books to tell you the background of a coin, the history or composition of a coin, and what's rare or not, you are going to get badly burned by unscrupulous dealers hoping you are not up to date on your stuff.

 

I'm not familiar with the tinning of Ancients. (I play around the fringes of ancient collecting with no specialization or in depth knowledge).

I'm not sure if this will help with the discussion, but Tin metal can undergo a crystal change around 50-60F. This crystal change causes the volume to expand and the piece can eventually crumble. It's commonly called tin pest.

https://en.wikipedia.org/wiki/Tin_pest

I would think that over the course of 1800 years +/-, a tinned surface would be exposed to enough temp variation to initiate the transition. Just my opinion, since I don't have the experience with these coins, but from the metallurgy side, I think it's a reasonable explanation against the existence of many tinned ancients.

 

You could all be right. The fact is that Wildwinds have shown 3 examples of Aurelian which were struck in Rome, listed and described as "Tinned". I think that tin as a metal might protect copper more than silver ( though I'm not a metallurgist). Besides it's cheaper than silver. Remember how the Romans resorted to billon instead of solid heavily-based silver. Why should we think it impossible for an ancient Roman coin to have been tinned? I mean isn't it worth trying to analyse or melt the coin to find out? In my humble and curious opinion, I could offer my coin to the Lab.

 

This has been done with hundreds of coins. Their surfaces are "silvery" due to sliver. It is, of course, possible there are exceptions due to unofficial production or modern reproduction.

 

If there was evidence that this one particular coin was somehow materially different then maybe, but the only evidence here seems to be a Wildwinds description and the thing to keep in mind is that Wildwinds is by and large a bunch of descriptions copied and pasted, errors and all, from dealers over the years, many of whom were using outdated references or references which they honestly don't understand how to read(a lot of dealers today still make similar mistakes). At this point you'd likely be destroying a coin just to find out that like all the others it was actually silvered.

 

Here's my silvered ORIENS AVG antoninianus of Aurelian.


Aurelian AD 270-275.
Roman silvered billon Antoninianus, 3.60 gm, 21.7 mm, 6 h.
Rome mint, officina 9, issue 11, early – September AD 275.
Obv: IMP AVRELIANVS AVG, radiate, cuirassed bust, right.
Rev: ORIE-N-S AVG, Sol walking r., holding olive branch in r. hand and bow in l. hand, l. foot resting on a captive in oriental dress kneeling on the ground to r., head turned l., r. hand raised; * in left field, XXIR in exergue.
Refs: RIC 64; MER/RIC temp 1834; RCV 11569; Hunter 23; Cohen 159; La Venera 1321-32.

Notes: This reformed antoninianus of the mint of Rome depicts Sol Invictus holding an olive branch and bow and treading on an enemy in Oriental costume. In the exergue, the initial R(oma) follows the mark of the reform XXI. Normally, a Greek officina letter appears before the XXIR on this issue; however, on this coin from the 9th officina, a star in the left field allows the letter Θ (= the Greek numeral for 9) to be circumvented. The letter was considered a bad omen, being the first letter of thanatos, the word for death, and which was used in funerary epigraphy.

 

I have a page about the metallurgy of Constantinian bronzes and a section about the silvering process --

http://www.constantinethegreatcoins.com/metallurgy/


and an interesting article

“Experimental Investigation of Silvering in Late Roman Coinage.”

 

Coupla Aurelians - super silver, they just SHINE so bright!

(Long-Neck Budweiser version)

RI Aurelian 270-275 CE AE Ant Concordia-Milit


RI Aurelian 270-275 CE AE Ant receiving Globe from Jupiter

 

I know that in the Eighteenth Century (AD) the British tinned their bayonets to retard rusting, especially on those destined for use by marines on board ships.

 

( disclaimer, not an ancient collector, so....)
Tin has a melting point about half of bronze ( varies according to %) whereas silver is slightly above bronze. I always assumed the bronze coins were dipped or immersed briefly. I would think the populace at that time would have few ways to differentiate silver from tin. It would be simple to immerse bronze coins into melted tin, with no distortion or damage to the bronze coin. Jim.

 

Why are we still talking about tin? A quote from the article that I linked to

"The production of the thin silver plating on the surface of the coins in the late Roman period has been subject to extensive research."

nota bene - silver plating and extensive research.

 

You got my best answer hoopster on that one

 

Already gave away my best answer. Should of posted earlier

 

And how many do you think read that article, Victor? In all honesty, I believe we need to consider the fact that the silvering process had to be accomplished in a way that could produce a million coins a week so hot dipping was not practical.

I propose a test of the other likely technique mentioned in the article. We need to place a large quantity of coins or blanks (need to determine when we think the silver was added) in a large vat of an amalgam of silver and mercury. Then we need to assign a minimum wage grad student/intern (closest thing to a slave currently available) to paw through the mess with bare hands until well coated and transferred to a similar vat of olive oil before spreading out to dry. The residual mercury would evaporate off in time as I understand it. It might be necessary to change the slave/interns every so often. I doubt there would be any trace mercury after 100 years let alone 1600???

I collected coins as a child. My mother was a nurse. She brought me trash mercury from broken thermometers and I loved playing with the stuff. One thing I did was making silvery pennies by rubbing mercury on with my fingers. If that is not a sufficient excuse for all the faults of my generation, my father used to take me out to watch the crop duster planes spreading DDT. It was the kind of sight that made you look up in amazement with mouth agape and saying aaaahhh. I don't want to hear even a suggestion of concern that silver plating coins might have an impact on mint worker slaves.

http://www.mylot.com/post/1906068/has-anyone-ever-heard-of-husk-drawing-salve
Every boo-boo I had as a kid was treated with HUSK salve. The hospital bought it in huge crocks and used it as surgical dressing before everything contained antibiotics. Like the link above mentions, it was another mercury containing thing from my past.

 

only the people that are actually interested in the topic.

for those few people, the webpage I linked to has many more sources.

 

I imagine that many of us in this generation were fascinated by the liquid metal Hg. When I was a kid, I used to get small amounts of it from the dentist and use it to coat silver coins, making them slippery.

It should be noted that elemental mercury is VERY impervious to being ionized by contact with anything, including stomach acids, so even ingestion of elemental mercury is unlikely to be the cause of any long-term adverse effects (elemental Hg will pass through the gastrointestinal tract pretty much without any absorption into the bloodstream). The real damage is caused by mercuric compounds that can break down into ions if absorbed or ingested and get into the bloodstream and tissues.