Featured The Beauty of Impermanence

Discussion in 'Ancient Coins' started by robinjojo, Sep 29, 2020.

  1. robinjojo

    robinjojo Supporter! Supporter

    The ancient bronze and silver coins that we enjoy, with their colorful and often dramatic patinas, are the product of centuries, even millennia, of exposure to the elements, primarily air and water, but also other chemicals that might be present, especially if they are buried. Being the objects produced by humanity, they are, nonetheless, composed of naturally occurring elements, namely copper and silver.

    Here are two bronzes from my collection:

    Roman Empire, 238 AD
    Sestertius
    Pupienus
    Obverse: Laureate bust, draped and cuirassed bust right.
    Reverse: Victory standing left.
    RIC 23a, BMCRE 58, Cohen 38
    Deep green patina
    19.91 grams
    29.5 mm, 1 h.
    ex Harlan Berk

    D-Camera  Roman Empire, Pupienus, 238 AD, sestertius, Vicotry, 19.1, Berk, g. 9-29-20.jpg


    Byzantine Empire, 539/40 AD
    Follis
    Justinian I
    Nicomedia
    Year 13
    Officina B
    Obverse: Helmeted and cuirassed bust facing, holding globus cruciger and shield; cross to right.
    Reverse: Large M, ANNO to left, XIII (year 13) to right, cross above, NIK in exergue.
    DO-117b
    Green/brown patina with some earthen highlights.
    23.8 grams
    39 mm, 5 h.
    ex Harlan Berk


    D-Camera  Byzantine Empire, Justinian I, follis, Nicomedia,, yr 13, Officina B, 23.8  g. 9-29-20.jpg

    Copper and silver, as we know, are highly reactive to exposure to water and oxygen. The greens, blue/greens and browns are the chemical changes that occur on the surface, altering the metal to an oxide, creating veneers, some thin others quite thick, of varying colors.

    Oxidation is an universal process that produces continual change in Nature. Indeed, it is a vital process for the sustaining of life on our planet.

    In the natural world, deposits of oxides of copper exist in abundance. Much of the copper that we use today, and over the centuries, has been obtained through the extraction of copper oxides, including malachite, azurite and cuprite, and the refining of these and other ores.

    Malachite (Cu₂CO₃(OH)₂)
    Ural Mountains
    Sverdlovsk Oblast, Russia
    474.5 g

    D-Camera  Malachite,  Urals,,Sverdlovsk Oblast, Russia,  474.5 g. 9-29-20.jpg

    Azurite (Cu3(CO3)2(OH)2) and Malachite (Cu₂CO₃(OH)₂)
    Bisbee, Warren District,
    Mule Mountains, Arizona
    297.8 g

    D-Camera  Malachite and Azurite,  Bisbee, Mule Mountains, Arizona,  297.8 g. 9-29-20.jpg

    So, the next time you look at your bronze and silver ancients, think of how much they have changed since coming out of the mint, and how they are continuing to change, along with just about everything else.

    “No permanence is ours; we are a wave
    That flows to fit whatever form it finds:
    Through night or day, cathedral or the cave
    We pass forever, craving form that binds.”
    ― Hermann Hesse, The Glass Bead Game
     
    Last edited: Sep 29, 2020
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  3. AnYangMan

    AnYangMan Well-Known Member

    While we are on the topic of copper/bronze oxidation, which is an entire study on its own especially helpful when studying ancient chinese coins and their crusty patinas, I thought I would share a picture I recently took of cuprite and cerussite crystals forming on a Northern Song cash coin!

    [​IMG]

    Oh and the block of Malachite you show has the typical botryoidal shape that you frequently see when the mineral appears in the 'wild'. On coins a green malachite patina will generally be very smooth, but every so often under special circumstances, a patina consisting of botryoidal malachite will form! Such as on this Qian-Yuan:

    [​IMG]

    Or on this Vietnamese Rebel cash:

    Tran1.jpg
     
    Last edited: Sep 29, 2020
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  4. robinjojo

    robinjojo Supporter! Supporter

    Nice photos!

    What type of lens did you use for the cuprite and cerussite crystals shot?
     
    Last edited: Sep 29, 2020
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  5. AnYangMan

    AnYangMan Well-Known Member

    A Sigma 105mm macro (f/2.8) at around MFD. You actually almost make them out with the naked eye!
     
  6. TIF

    TIF Always learning. Supporter

    Great shots, @AnYangMan, and interesting info!
     
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  7. Carl Wilmont

    Carl Wilmont Supporter! Supporter

    Thought-provoking post, @robinjojo, about how the fabric of coins reacts with the environment. @AnYangMan, those are outstanding examples showing the crystal habit on coins. Thanks for sharing them! In my view, the various patinas you see, particularly on bronze coins, add to their intrigue.

    It's neat when the patina matches the subject- for example, I like the way the green patina on this reverse adds to the realism of the leaf:

    upload_2020-9-29_16-23-13.png
    For completeness, here's the obverse:

    upload_2020-9-29_16-22-18.jpeg
    Judaea, The Jewish War. Æ Prutah (2.69 g), 66-70 AD. Jerusalem, year 2 (67/8 AD). 'Year two' (Paleo-Hebrew), amphora with broad rim and two handles. Reverse: 'The freedom of Zion' (Paleo-Hebrew), vine leaf on small branch with tendril. Hendin 1360;TJC 196. Wonderful jade-green patina with sandy highlights, and finely detailed and well centered. Extremely Fine.
     

    Attached Files:

    Last edited: Sep 29, 2020
  8. ancient coin hunter

    ancient coin hunter I dig ancient coins...

    One of my more reactive coins, with quite a green obverse.

    Caracalla.

    MACEDON, Thessalonica

    Caracalla. 198-217 A.D. AE 26, 14.9 grams, 7h

    Obverse: Laureate and cuirassed bust right

    Reverse: Nike advancing left, holding a small Cabeirus and palm

    Reference: Touratsoglou Em, II:a

    ex: JAZ Numismatics

    [​IMG]

    [​IMG]
     
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  9. Carl Wilmont

    Carl Wilmont Supporter! Supporter

    @AnYangMan, would you assess the green patina on this coin to also be botryoidal malachite? It appears to have the globular form in places, and looks similar to your last example.
    upload_2020-9-29_16-54-50.png
    upload_2020-9-29_16-55-48.png
    Judaea, Hasmonean Kingdom. Mattathias Antigonos (Mattatayah). Æ 4 Prutot (6.93 g), 40-37 BC. Jerusalem. 'Mattatayah the High Priest' (Paleo-Hebrew), cornucopiae tied with ribbons, decorated with vine-leaf and grapes. Reverse: BACI ANTIΓ in two lines within wreath tied at left. Hendin 1163; TJC 37a. Red-brown and green patina.
     

    Attached Files:

  10. Broucheion

    Broucheion Supporter! Supporter

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  11. robinjojo

    robinjojo Supporter! Supporter

    That's a lovely, contrasting patina on your coin.
     
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  12. AnYangMan

    AnYangMan Well-Known Member

    Malachite appears in many shades of greens and forms! While its single crystals are almost never visible, especially on coins (It would be extremely cool), in contrast to the cuprite and cerussite crystals above which are large enough to identify with the naked eye, it is the mass of malachite that in some cases can be botryoidal. Often also called ‘swirly Malachite’; especially on the Vietnamese coin you can see why. There are various other minerals that have the same mineral-habit and that appear in the same manner on coins, including spertiniite (from a single Southern Song hoard), smithsonite (high zinc coins) and even cornwallite.

    A Botryoidal texture (from the Greek for 'Grapes', I guess you can see why) can for example happen when there is a small particle of some sort, sand or a rough (casting) surface, that has radial crystal growth around it; this forms a sort of globule. It is quite normal for coins and can be seen on the coin @Broucheion posted (and I think I see a globule or two on @Carl Wilmont ‘s coin). A sort of small semi-sphere, looks like a bubble. But on their coins you see a lot of malachite growth that was not around such a particle but just on the coin’s surfaces, meaning the botryoidal structure, or something very much like it but not as perfectly round, only shows up occasionally. On the two examples I posted, the same process happened, but just with a lot more radially growing botryoides. These then fuse together after they keep growing and voila, you have that bubbly texture that we call botryoidal! In reality the process is a lot more complex and has to do with the conditions in which the coin is deposited as well. The first example I posted is especially clear; you can make out all the little bubbly botryoides!

    Ps. I too am no expert chemist or geologist, but had the privilege of learning a thing or two from an expert chemist with a specialisation in bronze patination!
     
    Last edited: Sep 29, 2020
  13. robinjojo

    robinjojo Supporter! Supporter

    Malachite is a fascinating mineral that forms as crusts, botryoidal (grape-like) forms, crystalline forms and in massive forms.

    The Russian specimen is a classic example of the massive form. So massive were the Ural deposits of high quality malachite that the tsars used it for table tops, large vases, panels and other decorative objects. There are many example of this type of malachite in the Hermitage and other world museums.

    Here's a photo of the malachite room, Winter Palace, St. Petersburg, Russia:

    [​IMG]
     
    Last edited: Sep 29, 2020
  14. ominus1

    ominus1 Well-Known Member

    pur D!!
     
  15. Roman Collector

    Roman Collector Supporter! Supporter

    I bought this one for many reasons (particularly because it depicts Faustina's growing family), not the least of which was its beautiful patina. I photographed it in sunlight so as to show off the patina:

    Faustina Jr FECVND AVGVSTAE S C Sestertius 2 sunlight.jpg
     
  16. robinjojo

    robinjojo Supporter! Supporter

    Beautiful patina. It makes the coin look almost like carved jasper.
     
  17. IMP Shogun

    IMP Shogun Well-Known Member

    Great thread, I also appreciate change:

    [​IMG]
    Arcadius 395–408 A.D. AE3 RIC X 62 Nicomedia
    D N ARCADIVS P F AVG / VIRTVS EXERCITI SMNA
    emperor standing front, holding spear and resting hand on shield, head right, crowned by Victory struck as emperor 395-401

    [​IMG]
    Gaius Germanicus (Caligula) 37–41 A.D. As RIC 38 Roma
    CAESAR AVG GARMANICVS PON M TR POT / VESTA SC
    Vesta between SC seated left holding patera and scepter

    [​IMG]
    Nerva 96–98 A.D. As RIC II 86 AE Roma
    IMP NERVA CAES AVG P M TR P COS III P P / LIBERTAS PVBLICA S C
    Libertas, draped, standing left, holding pileus in right hand and short scepter, pointing up slightly to right, in left hand

    This is more of an olive drab green (thank you Veterans!) versus Caligula's jade.
     
  18. Marsyas Mike

    Marsyas Mike Well-Known Member

    A very interesting post. One of my favorite things about ancients are the incredible colors that develop over the centuries.

    Green globules? Globulesque?

    Constantine Chlorus as Aug Aug 2018 (3).JPG

    Constantius I Chlorus as Augustus
    (struck by Maximinus Daia)
    Æ Post-reform radiate
    (305-306 A.D.)
    Alexandria Mint

    IMP C CONSTANTIVS P F AVG, Radiate, draped, cuir. bust rt. / CONCORDIA MILITVM, Constantius r. receiving Victory from Jupiter l., Δ /ALE.
    RIC VI Alexandria 59a.
    (3.68 grams / 20 mm)


    This is one of those kind of messy bronzes that have a kind of piebald look - sometimes these can be pretty ugly, but I rather like this one:

    Aelius - As Spes Sep 2020 (0).jpg
    Aelius (Caesar) Æ As
    (137 A.D.)
    Rome Mint

    [L A]ELIVS CAE[SAR], bare head right / TR P[OT COS II] S C, Spes walking left, holding flower and raising hem of skirt.
    RIC II.3 2700 (RIC 1067a (as)).
    (9.73 grams / 25 mm)
     
  19. Alegandron

    Alegandron "ΤΩΙ ΚΡΑΤΙΣΤΩΙ..." ΜΕΓΑΣ ΑΛΕΞΑΝΔΡΟΣ, June 323 BCE Supporter

    Wow, @robinjojo , thanks for the association of minerals to coins. Nice.

    This patina always fascinated me...


    upload_2020-11-12_9-35-24.png
    KYRENAICA Kyrene Æ25 9.6g 250 BCE Diademed Zeus-Ammon r - K-O-I-N-O-N; Silphium plant; monogram SNG Cop 1278 BMC 16-19


    The green is beautiful on this one...

    upload_2020-11-12_9-37-14.png
    RR Anon AE Litra 241-235 BC Mars Beardless Horse Head GREEN Cr 25-3 S 594


    And this was always just a GOOBER in his hair...

    upload_2020-11-12_9-39-23.png
    RI Quintillus 270 CE Ant - Rome mint - Radiate-Victoria RIC Vi 33
     
  20. ambr0zie

    ambr0zie Well-Known Member

    This Commodus provincial (my first Commodus coin) is on the road and will arrive in a few hours. I have never seen this kind of coloring, can't wait to see it in hand.
    upload_2020-11-12_18-29-0.png
    Psidia, Antioch . I suspect it is RPC 7378.
     
    Last edited: Nov 12, 2020
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  21. robinjojo

    robinjojo Supporter! Supporter

    Since I started this thread in September, another coin arrived from Spain.

    This is a drachm of Ptolemy IV Philopator, Alexandria, 222-205 BC, weighing 66.15 grams.

    Aside from its weight, which is impressive, although much heavier examples of this type exist, the coin is notable for its patina, which my photo does not truly reflect.

    Here, the mineral deposition, or rather alteration, has given this coin a rich overall dark brown/green patina. Further, in the recesses, where moisture accumulates, the color is a deep green-blue. This green-blue actually extends, almost like a gradient over parts of the coin, creating a most pleasing combination of colors.

    This is my photo of the coin:

    D-Camera PTOLEMY IV Philopator AE Drachm, Alexandria mint. 222-205 BC, 66.15  g, 10-24-20.jpg

    Here is the same coin as photographed by the seller:

    [​IMG]

    Lighting makes all the difference. The coin is naturally rather dark, but with the right angle and light source, which I believe was likely a fluorescent source in this case (not filtered light, as in the case of my photo), the contrast becomes more dramatic, showing the cuprite (brown) and the malachite grading to azurite (green-blue).

    Artificial toning cannot replicate the subtle combinations of mineral oxides, and only time and chemical processes can create the wonderful colors and combinations on our treasured ancient bronzes, as amply shown by the excellent examples posted in this thread.

    Thank you.
     
    Last edited: Nov 12, 2020
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