Featured The Beauty of Impermanence

Not just an interesting thread, but a beautiful one as well. Here is another one that I though might show the "impermanence" as well as the difficulty in showing the chromatic aspects of an ancient coin.

A while back I got this Aurelian & Vaballathus tetradrachm on eBay. Sometimes it is a real surprise to see what cheap, unpromising material can look like in hand.

Seller's photos:



My photos in direct sunlight - it is still rather cruddy, but note the blue granules and green areas - this is one of my favorites in regards to color:




Egypt Potin Tetradrachm
Aurelian and Vaballathus
Year 2/5 (271-272 A.D.)
Alexandria Mint
[AVT K] Λ Δ AVPHΛIANOC CЄB, L, D & C bust of Aurelian right; across field, date (L B) / IAC OVABAΛΛAΘOC AΘHNO V [AVT] C Pω, D & D bust of Vaballathus r., L Є across field.
Dattari 5425; K&G 106.72
(7.85 grams / 20 mm)

 

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Today I thought I would add a silver coin to this thread.

It is an Egyptian tetradrachm of Ptolemy I Soter.

Burial has given this coin a very dark, mostly smooth patina, what is often referred to a "hoard" patina. Whether or not one finds this dark, almost black patina appealing is, of course, a matter of preference. However, I do think any attempt to remove it would have a very negative impact on this particular coin.

As far a attribution is concerned, the best I can do is identify it as Svoronos 124, Cyprus, possibly from Kition.

Egypt
Ptolemy I Soter
AR tetradrachm
Struck ca 310-305 BC.
Uncertain Cypriot mint, perhaps Kition.
Head of Alexander right, wearing elephant's skin headdress / AΛEXANΔΡOY, Athena Alkidemos walking right, brandishing spear and holding shield on left arm. AΓ, monogram (YΓK)? and eagle standing right on thunderbolt in right field.
Svoronos 124; BMC 43.
With original “hoard” patina
14.7 grams

 

Is the reason why the hoard patina becomes of this kind of fabric, that there are a lot of silver coins going through oxydation together?

 

This is a kind of bronze coin patina that I find very beautiful, but also very difficult to photograph; the black, hard and glossy patina. There is quite a lot of pitting, unfotunately, but I don’t dare to do anything with this coin, as I fear any action will make it worse.




Phrygia, Apameia. AE22. Roman Protectorate 133-48 BC

Obverse: Laureate head of Zeus right
Reverse: AΠAMEO MANTIΘE ΔIOΔO, cult statue of Artemis Anaïtis facing; magistrates MANTIO and IOO.
Reference: SNG Copenhagen 180; BMC Phrygia pg. 84,86; SNG von Aulock 3471; Laffaille 513 var.

Diameter: 22 mm. Weight: 8,37 g. Conservation: very fine.

 

I agree that anything you do would make it worse.

 

I think that is generally the case. My experience with sea salvaged coins is that the degree of oxidation, the way the coin reacts to the conditions it is in, be it soil or salt water, is determined by its location in the hoard. Generally speaking coins on the periphery of a mass tend to have heavier deposits when compared to coins that are more towards the center. The outer coins react more with water, air and soil conditions than do coins towards the center of mass. Indeed, coins found on the outside can be severely corroded, while coins in the center can be almost unaffected.

 

I got this coin just today, and it's already up in my top 10 of 2020 (despite having only bought 3 coins so far...)

Anyways, it is the most lovely minerals I've ever seen on a coin.

There is blue and green, front and back.
The green I believe is malachite, and the blue appears to be crystals of Copper Sulfate.
(I'm probably wrong, please correct me)

The green is rather smooth and the blue, especially on the reverse, glitters at the right angle.

 

I do like this thread - glad it keeps coming back up.

Here's one I just got that I really like - a heavy sand patina on a Macedonian bronze of Kassander:

Macedonia Kingdom Æ 18
Kassander
(c. 317-305 B.C.)
Pella or Amphipolis mint
Head of Herakles right, wearing lionskin / BAΣIΛEΩΣ KAΣΣANΔΡO[Y] above and below youth on horse right, YΠ? monogram right field, Θ? below.
Mionnet I, 783 ? (see notes).
(5.68 grams / 18 mm)
eBay Dec. 2020 $4.99

Attribution Notes: Monogram right is similar to:

1. Wildwinds: YΠ monogram in upper right field, Θ below. Mionnet I, 783; Babelon Paris Inventory 1247.

2. Wildwinds: ΦΛ below horse, SNG Cop 1146 corr.; this looks like monogram to right on mine.

 

Nice coin!

Mineralogically speaking the blue is very likely azurite (Cu3(CO3)2(OH)2), a cousin of malachite (Cu2CO3(OH)2).

 

That's a nice example of a sand patina.

 

I have been experimenting with my old Leuchturm digital microscope. Here are some extreme close-ups of the surface of some tiny unofficial issue Vietnamese cash, circa 16th-early17th century.

Nice details of malachite, azurite and cuprite crystals on the surface.

SC

 

this one has a cameo effect with the gold toned silvering



Severus II
A.D. 305- 306
27x31mm 10.4g
FL VAL SEVERVS NOB CAES; Laureate head right.
SALVIS AVGG ET CAESS FEL KART; Carthage standing facing, head left, holding fruits in both hands; H in left field.
In ex. Γ
RIC VI Carthage 40a


some blue



Constantine I
A.D. 306- 307
Radiate fraction
19x21mm 2.2g
FL VAL CONSTANTINVS NOB CAES; radiate, draped and cuirassed bust right.
CONCORDIA MILITVM; Prince standing right in military dress, receiving Victory on globe from Jupiter l. leaning on scepter; A in center.
In ex. ALE
RIC VI Alexandria 85

 

Inspired by @Marsyas Mike :



I don't know why the patinas are so unusual on so many of these late Alexandria coins. It makes me wonder if they spent time in seawater in Abukir Bay or something.

Stephen Williams (1985) says that you can draw a line between the rebellion in Egypt in 297-298 and the Great Persecution. Diocletian thought the Egyptian rebellion had been instigated by Manichean coreligionists of the Persian Emperor. Seems like a stretch to us, but Diocletian thought so, and he didn't want Christians to be a fifth column like the Manicheans. Of course that rebellion is what brought the system of Roman provincial coinage to an end.

 

Amazing photos! What power lens did you use?

The green deposits of malachite deposit appear to be botryoidal (rounded) there appear to be micro crystals of azurite.

Botryoidal, a term used in minerology, simply means having a shape reminiscent of a cluster of grapes, a rounded surface deposit. When we're talking coins, it is the green oxides that can vary in shade. In minerology the copper oxide deposits, such as in The Democratic Republic of the Congo are extensive, and a prime source of copper ore for the world's economy.

Here's a typical polished example of the malachite from that country:

Malachite, Shaba Province, Democratic Republic of the Congo.

70mm x 53mm x 31mm

286 grams



As can be seen, the shades of green vary from layer to layer. The darker bands have a higher concentration of copper oxide compared with the lighter bands. Such variation can also be seen frequently on ancient bronze coins. Depending on deposition conditions, green and alter with blue (azurite), and shades between.

 

Ptolemy II Ae Diobol Unknown mint in Sicily 264-263 BC Obv, Head of Zeus right laureate. Rv Eagle standing left on thunderbolt. CPE B 297 Wolf & Lorber Subgroup 3 H69 This coin 18.84 grms 26 mm Photo by W. Hansen
This coin has to have the most amazing patina. It is a deep emerald green except on the reverse where it is predominantly black. This is one of the coins minted in Sicily.

 

Yes, that is a beautiful patina.

I would speculate that a deposit of cuprite on the reverse comprises the dark areas, likely over the green patina, but I would leave it as is, with a very attractive contrast.

An excellent example.

 

Here's one more example of a mostly unclean coin that shows layers of oxide deposits.

In addition is earthen deposits, the oxide layers, with round deposits, is quite apparent, especially magnified.

Roman Empire, dated CY 163 = AD 226/7
Æ32 of Neocaesarea, Pontos.
Severus Alexander
ΑΥ ΚΑΙ Μ ΑΥ ϹЄΟΥ ΑΛЄΞΑΝΔΡΟϹ, laureate, draped and cuirassed bust right / [ΚΟΙ ΠΟ ΝЄΟΚΑΙ Μ]ΗΤΡΟ [ΔΙϹ ΝЄΩΚΟΡ], front view of a two storey nymphaeum; within, statue of Tyche standing left, holding rudder and cornucopiae; [ЄΤ ΡΞΓ] (date) below.
RPC Online 6529 (temporary); Çizmeli 244; Price & Trell fig. 71. 18.52g, 32mm, 11h.
Very Fine. Extremely Rare; RPC Online cites only four specimens of the type.
Lot 498, Roma E-Sale 75

 

Here's a sestertius of Sev Alex with a neat technicolor appearance, with a variety of oxides, minerals, encrustations, all sorts of cool stuff. And an extreme close up of the face.

 

This patina is one of my favorites. It's a lovely dark forest green with variations in the patina's color.
Unfortunately, a break in that patina led to major destruction of the obverse. But I like that reverse so much I'll forgive that obverse transgression.

 

I used the Leuchturm digital microscope, which is a weird beast. It has a focus adjuster but no true adjustment for magnification. You just move it closer or further away from the item.

Those were shot with the end of the microscope actually resting on the coin's surface. It has its own illumination so that works.

SC