Much Ado About Nothing?

[David Atherton]

Recently I've been re-cataloguing my collection and looking over each individual piece, some for the first time in over a decade. The coins are in paper coin envelopes organised in those traditional red coin boxes. Most of the time they are in a safe deposit box at my bank, but there are times when they come home for a visit. I haven't noticed any differences in toning with the silver or patina with the bronze. No special precautions are taken regarding humidity, either at home or, as far as I can tell, at the bank.

As I was reorganising my collection I came across a few coins provenanced to the 19th century. They're in fine shape and still nicely toned. These coins were collected before climate controlled environments and seem none the worse for wear. All this had me wondering why is there all this pearl clutching regarding coin storage? If it was good enough for a gentleman collector in the 1890s, or 1950s for that matter, why not us?

Doug Smith has a few coins from a collection that was formed between the great wars and were stored in homemade coin envelopes made from postal envelopes! I would wager those coins weren't stored in a climate controlled environment for many decades. They look perfectly fine today ... even after being stored in non archival safe paper envelopes for decades without climate control. I would love for him to show them here.

I'm just trying to understand what all the fuss is about concerning proper storage (or BD, the coin collecting boogey man) ... is it a marketing thing? Modern anxiety? By some folk's standards today no one pre 1950s or 60s could've collected coins! And no, I won't even bring up slabbing.

Here is an example of what I'm talking about. A coin purchased over 100 years ago and looks perfectly fine today.

Titus as Caesar [Vespasian]

AR Quinarius, 1.60g
Rome mint, 73 AD
Obv: T CAES IMP VESP P TR P CENS; Head of Titus, laureate, bearded, r.
Rev: VICTORIA AVGVSTI; Victory adv. r., with wreath and palm
RIC 535 (R). BMC 92. RSC 374. BNC 79.
Ex Harry N. Sneh Collection, acquired from Tom Cederlind. Ex Baldwin's Auction 42, 26 September 2005, lot 288 (part). Ex William C. Boyd Collection, acquired from W.S. Lincoln, February 1896.

 

So, again I ask, is this much ado about nothing?

Edited November 1, 2022 by David Atherton

[Qcumbor]

I would tend to agree with you David. Apart from periods of very high humidity rate around here (e.g. august storms), I don't care much. Yes, I use a desiccant in the place I store my coins, but that's all about it, and has been for the last 40 years, with no harm, as far as I can tell.

Q

[Roman Collector]

These concerns are very legitimate for modern coins. Improper storage can lead to undesirable toning and wear. 

But these concerns don't matter much for most ancients, as you rightly note. 

[dougsmit]

Opinion:  Part of the difference may be the change in coin cleaning as much as storage.  In the 'old days' we got coins with their natural protective surfaces intact.  That was more likely to be stable than the raw metal exposed through current electrolysis and chemical scrubbing which leaves the coin susceptible to attack from things like bronze disease.  Today people are obsessed with the lack of wear over surfaces and coins that might have been set aside as not worth the effort get 'processed' and sent to market.  Coin conservation does not come at coins per second pace.  Speed kills. 

https://www.forumancientcoins.com/dougsmith/feac16.html

Mention was made to my coins from the Bavarian Collection.  Mine were cast offs from the lot bought by Tory Failmezger at the NFA sale.  He kept the nicer ones and had the envelopes.  When his coins were sold, I don't know what happened to the envelopes.  For that matter, I have not seen any sales in the last 20 years mentioning Bavarian provenance accompanied by original envelopes.  I suspect most were trashed in 1993 long before anyone cared about provenance of low end coins.  Below is my illustration from my page showing the best of my envelopes and one of the least of my Bavarian coins.  I bought it for the stamp.  How many would pay more for the envelope than for the coin? Other than my mention (repeatedly over the last 25 years) of the Celator article has anyone here seen any Bavarian Collection coins?  I have not. Crying shame. 

 

Constantius II AE2 Centenionalis from the Bavarian Collection (#2799)
Siscia mint, 3rd officina, Cohen 142 (3 francs value)

 

[sand]

I've been collecting ancients for 4 years. During that entire time, I've been storing my ancients in Abafil velvet trays and Abafil cases. I haven't been using dessicants. I haven't noticed any bronze disease on any of my many bronze ancients, other than what may have been there when I bought the coins (I'm not very good at telling the difference between bronze disease versus verdigris or green patina or other inert green deposits). I haven't noticed any significant toning on any of my blast white silver ancients. However, I don't mind toning on silver ancients.

Perhaps, if someone's coins were stored in a hot and/or humid environment, with temperatures that fluctuate between hot and cold, then perhaps condensation of water from the air, combined with any chlorine in the air or on the coins, or if the coins are stored in plastic flips (even non-PVC flips), perhaps that could cause or increase the spread of bronze disease, or perhaps cause destructive green slime on silver coins, but I don't know. I'm not an expert in bronze disease or green slime.

An expert once mentioned, that many ancient coin collectors are excessively worried about bronze disease, and that many ancient coin collectors incorrectly believe that relatively inert green patina is bronze disease. I don't know. 

I have a theory, that the difference between bronze disease and green patina is time, at least in some cases. That is, perhaps, bronze disease eventually becomes green patina, at least in some cases, perhaps over hundreds or thousands of years. However, it's just a theory, from my non-expert mind.

On the other hand, I think I may have read somewhere, that bronze disease involves chlorine, and that green patina does not involve chlorine. I don't know.

Edited November 1, 2022 by sand

[Limes]

9 hours ago, David Atherton said:

I'm just trying to understand what all the fuss is about concerning proper storage (or BD, the coin collecting boogey man) ... is it a marketing thing? Modern anxiety? By some folk's standards today no one pre 1950s or 60s could've collected coins! And no, I won't even bring up slabbing.

 

Maybe I missed what's going on about climate controlled environments for storing coins? I only know those from keeping cigars in fancy restaurants 🙂 A friend has a special refrigirator of some sort for keeping his wine. I'm not fancy enough to taste a difference though.  

Hence, I sure am not 'gentlemen' enough to store coins in a perfectly articificial storage environment. Nope, I simply keep them in a couple of red trays, which stand up in our cabinet, for everyone to see (which in practice means I only look at them because nobody cares). The trays contains squares. One has round spaces in the squares, of 20 mm in size. The other tray just the squares, which measure 40 mm. The first one is for denarii, the second one for the big bronzes. I use round plastic devices for the big bronzes, which I can cut into the right size, and place those in the square, so the coins wont 'slide down'. Some other coins that don't fit (middle bronzes) are in small standards or a small display case. My collection is small (130 something), and I like that I can always look at my coins, take them out, touch them, reorganize them etc. I've bought two coins in slabs, which were taken out, because slabs don't fit in my display cases. 

In a Dutch museum in Leiden (antiquities) there are some denarii on display, of the 12 C's. Those are the only 'old cabinet' toned coins I've seen. They look like the old silverware of grandmother that has not been cleaned for ages. I absolutely love that toning, and even though I dream of it, I don't think that kind of toning will ever be achieved in my cabinet. (If anyone has some advice, please let me know.)

1 hour ago, sand said:

I have a theory, that the difference between bronze disease and green patina is time, at least in some cases. That is, perhaps, bronze disease eventually becomes green patina, at least in some cases, perhaps over hundreds or thousands of years. However, it's just a theory, from my non-expert mind.

 

I've had three issues with BD (collecting for 7 years), when little green, powdery spots emergedon the coin. All three the coins had signs of earlier issues (pitting, no patina on areas), but were to some extent clean when I got them (in my eyes, at least). But nothing that a bath in DW won't fix. I dont think it has to do with the environment in my house. 

As I understand it, the green (and brown, and black) stuff we call patina, is a (mostly) solid layer caused by some sort of chemical reaction between coin and soil, which forms over time and actually protects the coin from the environment. BD on the other hand (and in my limited experience) seems to appear on the areas where there is no patina, and interacts with the core metal in an agressive way, actually biting in to it, so to say, causing e.g. pitting. But then again, I should stop talking now because I'm no expert 🙂 There are online sources on BD and how to treat it though. 

[John Conduitt]

9 hours ago, Roman Collector said:

These concerns are very legitimate for modern coins. Improper storage can lead to undesirable toning and wear. 

This is where most of the concern comes from. The same as the obsession with slabbing. Obviously, people can't stop a natural process, so in the long run it's futile. But if you buy modern silver coins because they're mint state and they start to develop spots, it ruins them (until 100 years later when that is just the toning).

Once something tones, it will just get darker, which might not be desirable. It takes a long time, though. So for old silver coins, there's no reason to worry about the environment as long as it isn't very harsh. Gold can sit in the ground for 2000 years and not change, so there's no worry about that either. Bronze coins with a patina will be fine too, but if they needed cleaning, there's a risk of bronze disease.

Remember, though, that Victorian collectors did worry about climate control. They covered their bronze coins in wax to protect them. Which we now clean off, putting them at risk of bronze disease again.

1 hour ago, sand said:

I have a theory, that the difference between bronze disease and green patina is time, at least in some cases.

I don't think it is. Bronze disease is devastating and can explode over a coin, visibly eating it by the day and never producing a protective coating. It can spread to other coins it touches. Green patina, on the other hand, is stable and protective. (The main thing patina protects against is bronze disease, because it already reacted with the coin's surface in a non-destructive way).

Edited November 1, 2022 by John Conduitt

[Theodosius]

A lot depends on the average humidity of the location you live. Bronze disease is much more active when the humidity level is over 50%. If you live in Florida where the average humidity is 60-80% then it is a real problem.

It is also a problem when a coin was discovered in a dry, desert location like Egypt the Middle East etc and then made its way to someone in a very humid climate, then there is a chance that bronze disease will become active.

Bronze disease does not turn into hard green patina. It is a catalyzed reaction, the chlorine atoms causing it are not consumed by the reaction, they catalyze it. So they are never used up. If left untreated in humid conditions bronze disease will cause a lot of damage and never stop. The only way to stop it is to neutralize the chlorine atoms by binding them to some stable chemical like a base, or removing them through distilled water soaks and scrubbing.

I too have bronze coins I bought 40 years ago that are still fine despite living in Florida the whole time. Usually it is new coins coming to me that reveal they have a problem after 6 months or a year. As Doug points out how they were cleaned has a lot to do with it too. If the original protective patina is damaged and bare metal is exposed that contains chlorine atoms then look out if you live somewhere humid.

John

[robinjojo]

I look at bronze disease as a pre-existing condition, using a medical term.  I use that term because the presence of the conditions that create bronze disease (BD) take time to form, considerable time in fact.  The powdery chemical reaction usually is part of a coin as it remerges from the ground, often forming in conjunction with a thick red patina.  I should hasten to say that not all red patina has BD, but at times there seems to be an association.  Regardless, BD, even in seemingly incipient amounts, needs to be treated since it is a progressive, actively corrosive chemical reaction.

Storage conditions, such as humidity can affect toning for silver coins and patination for bronze coins.  It could even reveal some BD that was not initially apparent, as in the case of a BI tetradrachm of Caracalla that I received without any indications of the problem, probably due to the likelihood of the coin having been recently cleaned.  The coin was in a safety flip when I saw the corrosion making its appearance.  The coin has been treated and so far the BD has not reappeared.  

It is important to remember that ancients, unlike most modern coins possibly with the exception of coins that were salvaged or buried, have been exposed to the elements for thousands of years, generally, and that any attributions to storage in the 19th century, aside from obvious tooling, cleaning, etc., can be tenuous, since it is difficult, at least for me, to know what condition the coin was in back then at the time of storage. 

Edited November 2, 2022 by robinjojo

[Deinomenid]

I'm not sure  how  much in the old days (I mean 100 years ago) coins were  left alone. I'd previously assumed they were generally not chemically altered or "helped" until I managed to trace a few coins  back to the 20's and found comments such as the following from Ratto 1926. That they highlight this particular collector's coins were untouched - when in most of their catalogues they do not - implied to me that tinkering was common.

 

"The rich collection presented in this catalogue has been formed by a savant collector, well-

known amongst amateurs of Roman numismatics, who has consigned it to me for sale by

auction, requiring that I do not disclose his name. It was started in about 1910 and has been

continued up to the present day, with some pieces, including the more important, being acquired

as recently as the Bement sale of 1924. I must explain one important fact. The owner did not like

his coins to be artificially cleaned by chemical processes or re-touched with the burin. All the

bronzes are replete in their natural beauty with their patinas preserving the usual encrustations.

These do not detract from their beauty but through photography and the plaster cast process

they become conspicuous on the plates, giving the illustrations the appearance of a secondary

quality."