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Hello all.

Would anyone like to comment on the black patina on this archaic bronze jue we recently acquired?
We purchased it from a Japan based dealer, where it was in a private collection.

We've tested the patina against water, acetone and mineral spirits, and it seems firmly fixed natural. Anyone know if this could be simulated with liver of sulphur, and if so how could it be detected? Could malachite or azurite crystals be embedded deep inside a fake liver of sulphur coating?

We believe that this made from several separate bronze pieces placed inside a body mold - not a single lost wax casting, and no brazing.

We think the piece is possibly a genuine Shang or Eastern Zhou archaic bronze made from a high tin percentage bronze alloy.

Bronze experts, what say ye???


Thanks all for any comments and assistance.

Doug and Moyra

Hello Doug & Moyra,

The first corosion substance on old bronze is CUPRITE, an ox blood color mineral.

On cuprite will grow the second form of corosion, Malachite, a green color crystal/mineral.


On malachite will grow the 3rd form of corosion, Azutite, the nice blue crystal/mineral.

To see if your piece is genuine, it is very simple & impossible to reproduce:

If you scratch the azurite, you must find some Malachite underneath.
And if you scratch that layer of malachite, you MUST find cuprite.
Azurite cannot grow on it's own, it needs malachite.
And Malachite needs the cuprite to grow on it.

There are no exception to that rule, if your piece is made of bronze.

Fake makers do normaly use paint to simulate cuprite, so check with a loupe and see if the ox blood substance is a crystal or what looks like red little chips. Chips = paint.

I cannot tell from your pictures if the piece is for sure genuine or not. I found the pale green substance on one of the leg kind of suspicious/not natural.
There are thousand of fake/copies of those kind of cups that could be found on the market.One of the fake makers favorite piece.

The real ones are rare and very expensive. But of course one cannot rule out a bargain, they do exist, sometime.

Good luck,
Pierre

Thanks Pierre.

Well if only it were that simple...

Under the greenish surface is... solid black patina. And under that finely gritted patina is silverish metal. What does all this mean? Fake? Maybe - or maybe not. This jet black patina and silverish base metal color is consistent with high tin alloys as commonly found on Eastern Zhou mirrors. And it's common knowledge that Zhou jue cups were produced on a large scale and hoards have been discovered with dozens or even hundreds of these cups. There are some embedded white crystals stuck firmly in the patina, and we believe this to be some sort of tin compound. You can see it on the third photo, under the handle.

And speaking about handles, what's up with the genetalia on the animal figure handle??? The face (popping eyes) are typical, but we've never seen one with a penis. Also, there appears to be some sort of phallic symbology on the taotie design on the mouth rim. This piece is really small - only 12 cm tall. About a third of the height of a typical jue. Some sort of fertility ceremonial piece??? There are enough differences between this and a typical Shang piece that we have a hard time understanding why someone would bother to create a fake this way.

All in all, a most interesting puzzle.

Here is some reference material from a University researcher discussing Eastern Zhou bronze mirrors:

The composition of the bronze alloy to cast the mirrors was carefully chosen. The mirrors are composed of about 70% copper, 25% tin and 5% lead. As Chase (1991) points out, pure copper is difficult to cast because of its high melting point, and the fact that it absorbs gasses, especially oxygen, while molten. After the copper is poured and cools, gas bubbles form resulting in a very porous metal. The addition of tin not only lowers the melting point, but also acts as a deoxidizer helping to prevent porosity. As more
tin is added, the color changes from red to yellow to silver and the hardness and brittleness increase. The addition of lead does not change the color, but up to three percent increases fluidity, helping the alloypour more easily during the casting process and any amount facilitates the ease of grinding and polishing.
Lead does, however, decrease the tensile strength, and leaded bronzes cannot be hammered or they will break. The copper-tin-lead ternary alloy that was used was very hard and brittle, but the silver colored metal took a very good polish and was ideal for a reflective surface.
The mirrors, however, are also found with a lustrous black patina. The color difference is one of the most intriguing aspects of these bronzes. The question is whether the black color was intentional or was the result of a silver colored mirror being buried for hundreds of years. This issue has been widely studied,
debated and is still not fully understood.

Thanks

Doug and Moyra

Dear Doug and Moyra

Your jue doesn't look like ancient bronze to me. It looks like the material that used for my alloy estate gate with intentionally making it crude and coroded to look ancient, while the authentic one is "neat".

-------------------
The jue vessels are used for drinking as a modern day pint glass. Jue stands on three legs and fire can be placed under the legs for heating. Two short stubs on top of jue are called Zhu.

-------------
Your jue is 100% reproduction with acid treat. The authentic one, the whole piece was casted in the mold, but your jue has trace of heating process to connect "Zhu" to the Jue body, which is unlikely to be seen in ancient jue. (see museum pieces attached).
------------

To support Pierre's corosion substance on old bronze theory, pls find attached useful.

Have fun
Anita Mui





URL Title :CHINESE ANCIENT BRONZE CASTING HOW TO

Execellent answer pierre, thank you, I didn't know that. Do you have picture to illustrate it?

This piece is modern shape looks han wine cup, but details shows fantasy decoration that correspond to no archaic bronze piece.(most of the time design is quite precise and thin).

Patina is highly suspicious too.

Can you see white spots on the surface (and inside the cup, white spot in surface holes and cracks)?

Thank you Anita and Pipane, for your input. We said we appreciate all comments, and we sincerely mean it.

From what we understand, pieces like this were not necessarily single cast using the lost wax method. They were cast in sectional clay molds, and often small pieces like handles and those Zhu knobs were placed into the mold, and molten bronze was poured on top. Traces of joints were often polished off. We know that the Zhu knobs on our piece were separate cast because one of them is tilted way off-center - something likely not to happen with a wax mold.

As far as the patina being odd looking, not necessarily. This black patina is consistent with high tin bronzes that have had exposure to water. It looks just like a black patina we saw on a Jue cup in the San Antonio Museum of Art. (That piece was much larger of course) Any yes, it certainly doesn't look anything like Anita's nice example. But that's a funny thing about bronzes. They can be composed of so many combinations of metals, and subjected to vastly different elements of corrosion, that no two end up looking alike.

Whatever the patina is, it's thick and it's on this cup firmly. It's not easily coming off. And those while spots are crystals firmly embedded in the patina. They could be some sort of zinc or lead mineral.

We really don't understand the complex chemistry here, but one thing's for sure. If we have the piece tested and the patina proves to be cassiterite (tin dioxide with silica traces from sand, etc) this is somewhat of a dependable marker for ancient Chinese high tin bronzes. It's not something that can be easily faked. From the ancient coin folks, bogus black patinas are normally created with sulfides like liver of sulphur, hence our initial question.

So we're going to find someone at the University of Texas in Austin with some metallurgical expertise, and bring the piece in to get an opinion. There are non-destructive spectroscopic tests than can readily identify common minerals.

We promise you that whatever the results of the test, we will post them here to share with you all.

Warmest regards,

Doug and Moyra

Dear Doug and Moyra

Pls look at the craftsmanship first, before you look at its sign of age.

Things are so different from the reality (see attached).

Have fun
Anita

Dear Doug and Moyra

I should say that your bronze jue cup shows welding and fabrication marks which ancient works could not achieve that.

Your piece may be "one of a kind", pls send to the lab to perform TL test to confirm the date of last firing.

Have fun
Anita

Have fun
Anita

Hello Pipane,

Here is a photo of a cut piece of bronze with external and internal corosion.
You can clearly see the cuprite on the bronze and the malachite on cuprite.

Dear Doug & Moyra,

The "old " looking aspect does not mean much, only the natural corosion sequence will tell you the truth.
Also to keep in mind is that, due to it's density, copper will get to the surface and tin will remain below the copper so to speak.
Phallic symbols on your cup seems to be a fantasy that, more than often, fake makers can't help to add to attract attention on the object.

All in all, I'm not optimistic regarding the authenticity of your Jue.
And please keep in mind the corosion sequences. I repeat, there is no way around it.

Have a nice week end,
Pierre

Hello all.

As a quick follow up, Dr. Zhao from the Geosciences department at the University of Texas in Austin has kindly invited me (Doug) to bring the piece to his lab on Wednesday the 10th. He is quite interested in the results, and will perform the test procedures himself. We should be able to determine the composition of the patina and whether it is natural, artificial chemical, or heat induced. We will share the results with you all then. We think this is a great opportunity learn more about bronzes and patinas.

In case you're interested, here's a link to UT Jackson School of Geosciences describing their lab facilities.

http://www.geo.utexas.edu/microbeam/

Please stay tuned!

Doug and Moyra

URL Title :UT Geosciences lab

Hello again D&M,

I just realized I did not answer your question:

"Under the greenish surface is... solid black patina. And under that finely gritted patina is silverish metal. What does all this mean? Fake? Maybe - or maybe not."

There are many old bronze pieces that does not have the cuprite corosion and therefore no malachite / azurite.

Those are the one with the nice smooth black patina, as you mentioned.
But, they are all black/silverish whatever, no green stuff only on it.
And yes, if there is a green surface and solid black patina underneath, then it is not natural thus fake.

Now, here are another few pointers to look at:
I guess you do agree that, if your piece is real, it was burried for a couple of thousand years and should show
- traces of hearth / hearth salt / roots / magnesium bioxyde.

As for the patina it should be
- smooth (is it on your piece? from the pics it seems not to be the case)
- show some black spots (lead)
- have an irregular silvery aspect at some places (tin to the surface)
- no light green powdery area (acid treated)

Another thing to look at is the air bubbles in the patina.
If allmost inexistant, your piece has a chance, but it seems that I see quite a important amount of them. That is a sign of use of modern welding tools.

It would be great to see the result of your test, thanks in advance for sharing.

Have a nice day,
Pierre.

Hi Anita and Pierre.

Anita, we understand your point but we don't think that our piece was braized. There are no surface lumps, and what you are pointing to is a flaking of the hard patina at the joint area of one of the Zhu knob. There is no flaking on the other knob. We think it's flaked there because it is a stress point for people prodding on that off-centered Zhu knob - trying to see if it can be bent straight by fingers. We did this ourselves, and who knows how many other people tried it before us. As far as the handle goes, it's tiny - like a demitasse cup handle, and is roughly finished under the casting. Fritz Low-Beer, the famous lacquer expert, said "Photographs are great liars. They make bad pieces look good, and good pieces look bad." We couldn't agree more!

Even if the pieces were braized on, that wouldn't be a problem. Braizing technology was available and used by the Eastern Zhou bronze makers.

As far as TL test goes, that's not an option as you can't TL test bronze. Bronze has has no memory like ceramic. In fact, there is no age test for bronze at all, as the metal is as old as the earth itself. The best one can hope for is authentication that the patina is made of natural corrosion products consistent with the metal composition. No one has yet been able to figure out a way to build natural corrosion products up into a compact and thick patina without time. The same cannot be said of chemical corrosion and heat corrosion, but those deceptions will come out on a mineral composition test.

Pierre, all we know from the limited research that we've done on black patina composition, is that it's not that simple for high tin bronzes. The tin goes through it's own corrosion cycle covering the piece, and copper only comes out in limited amount in a number of mineral forms. It's definitely not the case that copper migrates out, and the tin stays in - it's the exact opposite.

But rather than argue chemistry, a subject I (Doug) haven't studied in 20 years, let's just see what the lab analysis reveals.

Warmest thanks,

Doug and Moyra

I want to add that: white spots (white spots on black or original green patina) are mark of CaCO3 chemical reaction (used in metallurgy) that produce a lot of energy but also some white combined elements very hard to clean from bronze surface even with a metal brush.

Such white spot are often seen on reproductions in small holes on bronze surface or inside where metal surface is irregular.

it looks like what Anita pointed out...


Regards,

Pipane

Hi Doug and Moyra,
How many times in my early collecting years must I have wanted my latest purchase to have been some rare piece; only to find it had so many defects that authenticity was not only unlikely but impossible.
Sorry, but this black jue is in my opinion in the impossibility category.

Pierre, I don't know what text books or real bronzes you have researched, but your conclusive "there are no exceptions to that rule" are certainly not accepted by this author.

Azurite (not azutite) blue corrosion is in my experience found at its most brightest colour on the undersides or insides of bronze vessels, and to date has been one of the most positive visual indicators of authenticity.

Where on this piece is there evidence of antiquity?

Regards
Tony

Thank you all, for your comments!

And a special thanks to Anthony. We are well aware of your professional credentials, and honored that you shared an expert opinion with us.

The preponderance, (no make that unanimity) of experienced opinions is that, for a variety of reasons, this piece cannot be authentic. As such we must humbly assume that all of you are correct. Let's just declare it a modern fake.

But we still look forward to bringing the piece into Dr. Zhao's XRD lab. We are dying to know what this thick coherent black "patina" is made from, how it was created, why it did not react to traditional solvent tests, and how it might be more easily identified in the future.

Warmest regards,

Doug and Moyra

Dear Doug and Moyra

You said brazing technology, you hereby meant joining technology?

Yes, there was such technology for accessories parts of complicated bronze works but not for your jue. Your Jue is easy to do whole-piece-casting in a mold...not that complicated.

---------------------------------

"There is evidence of brazing and
soldering during this period. For example, the masks found at Sanxingdui were cast with
holes on each side of the head. The ears were cast later, inserted into the holes and
attached by soldering; the solder is visible from the interior wall of the mask (Figure 27)
[5]. The mask with protruding pupils seen in Figure 27 was cast in six pieces, five (2 ears,
triangular underside of nose, 2 pupils) were precast and embedded in the final mold. The
mold for the main pour required a rear section (or core) and one or two sections for the
front of the mask [5]. The square/rectangular shaped cutouts on the forehead and lower
jaws were for attaching large projecting ornaments."

Source:-

http://library.csun.edu/Collections/SCA/SC/Tseng/bavarian.pdf

---------------------------------
Watch youtube, Chinese Bronze Artifacts Exhibited in Canada, there's a info about Jue in there.

http://www.youtube.com/watch?v=0oMG0XhSIRE

Have fun
Anita

Dear Doug and Moyra

Sorry, my mistake.

TL test can be done on bronze artifacts, only there are fragments of clay mold from casting those bronze still intact, if there are none, the scientist will look for relative concentrations of major and minor elemental constituents of the bronze alloy using an energy-dispersive X-ray attached on a scanning electron microscope.

If there is some organic material attached to the ancient bronze, the scientist use carbon-14 dating, pls do not clean your bronze after purchasing.

Have fun
Anita

Hello all that have been following this thread.

Well, I'm back from the University of Texas Geosciences lab, and we learned quite a few things.

Dr. Zhou kindly spent quite a bit of time with me, and since this piece is so tiny, we were able to fit it into the vacuum chamber of the electron microscope and examine several parts of the piece non-destructively.

When I asked him what the patina was like, he answered in one word - complex.

It's not a black copper oxide crust that one would get if they heated a bronze piece with a blow torch.

Next, it's not homogeneous. We were looking at sections that were about 1 mm square that were blown up on the computer monitor to cover the whole screen, and he was able to place cross-hairs at all sorts of different places within this tiny area and read the chemical composition. Every area he moved to and the chemical composition changed significantly. That means that this was not some simple artificial coating done by dipping into chemicals.

He identified lots of copper of course, sulphur, significant amounts of lead, some zinc and iron, aluminum traces, phosphorous and silicates. There were many embedded microscopic crystals. Almost no tin was detected. Not many copper carbonates, and no real hydocarbons to speak of.

He basically said that this deposit was unoxidized - the minerals had formed in an oxygen depleted high sulphur environment. He identified the minerals as chalcocite, covelite and bornite - all copper minderals with out oxygen - with traces of silica (sand). He believes that the thickness of this patina is significant, and this could have taken quite a bit of time to form.

The first pass on the testing suggests that this piece is likely covered in a natural black patina typical of objects submerged in water.

Of course, it may be argued that given enough time and the right mix of chemicals and the right oxygen reduced environment, this could have been reproduced by a skillful scammer in a laboratory. But that person would really have known what they were doing, and it's a lot of effort for a piece that obviously doesn't look authentic from a style perspective to most experts.

In case you are interested, here is a photo of some of the boronite crystals inside the patina. If anyone understands this stuff and would like to see the entire series of photos and element traces, please email me and I will send you the raw data. Dr. Zhao suggested we send the traces to someone who specializes in archeogeology, and if we find someone we will.

Warmest regards

Doug and Moyra

Doug and Moyra

So, Dr.Zhou just investigated the mineral growth on the acid treated bronze? Those things can be grown by acid, and obviously no difference to see with electron microscope or naked eyes..acid treament is all natural mineral growth but quicker!..just like acid treated jade.

*your jue is small but can not be put in the machine?..what's this machine actually made for?*

It made me think of Dr.David who buy fake Hongshan jade from eBay and observed them with microscope, and think they are authentic with evidence of mineral growth...the only prove of authenticity he has.
----------------
You may use wet litmus paper to scrub / rub / patch on the mineral growth area, and observe any change.

1)Sodabicarbonate will turn blue litmus paper to slightly red.

2)Alkaline and Sulphuric acid will turn blue litmus paper to violet.
-------------------

Style and carftsmanship are not correct why you have to waste your hard earn money for proving it authentic. In case it is authentic, it values a little sum for that obvious conditions.

Have fun
Anita

Hi Anita.

Thanks for your comments.

I think that it would be useful to explain a few things here, and if any chemists, archeologists or geologists happen to be following this thread, please feel free to correct any of my mis-understandings.

The piece is 12 cm tall, and was small enough to lie on it's side in the vacuum chamber of a combination electron microscope and X Ray Diffraction analyser - a JEOL JSM-6490LV to be precise. This device could not only show photos of tiny areas, but had the capability to identify chemical signatures on tiny spots under control of the operator. It shoots X-Rays at a small spot, and measures the reflected patterns. These patterns are mapped by computer to show what % of what elements are present in the area sampled. What is presented to the operator is a graph, that the operator, Dr. Zhao, was able to interpret. Dr. Zhao is a professor at UT, and an expert in interpreting these graphs. He identified several minerals that made up the patina - specifically chalcocite, covellite and bornite. These are all compounds of copper and sulphur which are very difficult to synthesize even in a laboratory. These are not compounds that are produced by acids. It also happens that these compounds are commonly found in ancient bronze patinas. In fact, these minerals are most often associated with pieces which have been under water and subject to microbial action - commonly known as a "water patina".

The thickness of the patina means one of two things. Either it took a very long time to create this thick layer of corrosion products, or somehow somebody mixed up a sophisticated concoction of the right naturally occurring minerals and found a way to solidly adhere them to the surface. No organic binders were discovered, so the latter option is extremely unlikely.

We definitely know 100% that this piece was NOT acid treated. Acid causes oxidation (a combining with oxygen) and the minerals that were identified were unoxidized. So even though this may look like a piece that has been dipped in acid, it most certainly was not.

Why did I do this? I'm curious. I just wanted to know what this thick coherent black patina was made from. Do these tests prove that this piece is Shang or Zhou? Certainly not. But it is pretty likely that this piece, wherever it came from, is very old.

There are a couple of additional tests that could still be done, but the cost benefit of doing further tests is prohibitive.

Thanks again for your kind assistance!

Doug and Moyra

Dear Doug and Moyra

There's nothing wrong to seek the truth and fact, but there's an easier and cheaper way to do that..why we have to buy an elephant and sit on its neck just to catch a simple grasshopper.

Have fun
Anita

The most common way to make up great patina in one night....

Get a car battery, a deep plate, salty water, two electrodes...

get on board, get now your "antique" buried for 9 month...get it out clean a little bit, not too much...

But there must be hundreds of new techniques to make better fake.

What I don't understand is: was this post aimed at promoting a Lab or was it to promote a obvious fake?

Let's assume I am the mean one, it remind me that friend who bought a Dong minority dagger once on a flee market and had to get to China and then Birmania (at that time) to find what was the story of that dagger...

Thank you Anita and Pipane.

I'm well aware there are many ways to create fake patinas. That's why I sought expert scientific opinion. The piece was tested at one of the most advanced metallurgical research facilities in the world. The test results are unambiguous, compelling, and speak for themselves.

Cheers

Doug

Doug and Moyra

I admire your patience and persistance here. I think one thing is clear, ask two experts and you will get two different answers. I started collecting Chinese bronzes many years ago and have come to the conclusion that trying to prove that a piece is authentic without clear documented history is somewhat futile. I decided in the end that the artistic merit of the pieces I was buying was just as important to me as whether they were 2000 years old or not providing I wasnt paying huge sums of money. If you enjoy the piece then that is important.. I am sure one day we will have a clear cut method of age testing these pieces so until then I will wait and enjoy my collection for what it is...great art!

and to the experts.. it will be all of you who find the solution through these discussions!

SORRY BUT I HAD TO REACT.

Quote James: " I think one thing is clear, ask two experts and you will get two different answers."

Sorry but this is not correct, just the opposite in fact. That is by the way the purpose of an expert!

This is actually typically what I hear from people promoting fakes. Again, ask 10 experts about a good piece you'll get 1 single answer!!!!

that's obvious...think a little...

1-there would be no market at all if authenticity was a matter of perception...

2-bring a fantastic Shang bronze to any serious dealer/expert you'll get the same answer:that's a great piece...

The real problem is
-in 99% of the case people don't bring such good antique to authenticate and they are not ready to hear the truth...
-they don't get to the right person...you'll get one single answer if you ask 20 Chinese archaic bronze experts...if you start to ask the nick nack seller at the corner of the street that's another story...nobody is expert in everything...

At last it is quite easy to authenticate and date a archaic bronze...spot recent repairs and old defects in structure is quite easy too...I mean for people in the field...

I don't see the point of using a bazooka to shoot a fly. Should we discuss this astonishing result further more?

And I forgot, do you know archaic bronze can't be dated by carbon14 analysis?

Regards,
Pipane

Hi Doug and Moyra,
Curiously you do not give the breakdown of the various elements in percentages?
The presence in any quantity of either zinc or aluminium, especially when in combination with a low tin content, are almost certain indicators of fakery.
Also, azurite blue corrosion in my experience is never present in equal consistency over the entire object.
Sorry, I remain unconvinced.
Regards
Tony

Thanks for your wise observations James and your questions Tony.

Tony, I am going to email you the complete results of the XRD and SEM scans with all the photos and chemical composition data. There are 17 sample areas taken from the handle and body. What you are going to see is wildly varying heterogeneous chemical composition. Down to the micron level. Remember, this is not an analysis of the metal itself, but is an analysis of the corrosion product layer.

This layer is made up of elements which have migrated from the base metal, and combined with elements from the environment. The elements identified could have originated in the metal as impurities, or come from the environment -likely both. A comprehensive base alloy analysis would tell the tale, but for time and cost reasons was not done.

The environment may have been a wet burial site, and the unoxidized sulphides and chalcopyrite are likely to have been created by a biofilm of SRBs - Sulphur Reducing Bacteria. The other trace elements commonly come from the aqueous environment. You will see all sorts of interesting chrystalizations and silicate inclusions.

We did NOT examine the powder blue surface corrosion, as we ran out of time. But seeing as the corrosion products are mostly sulphides, it is quite possible that the blue material is an oxidized sulphate that's developing post-excavation. This piece still has sand embedded in the patina indicating it was excavated.

I would like you to particularly notice test # (also page #) 15. This shows 99.07% Cu, 0.93% Sulphur and NOTHING else. What you are seeing is known as an Unalloyed Copper Inclusion (UCI). These have been observed on ancient buried bronzes, and have been researched in recent years.
These crystals of pure metallic copper are sometimes created within built up over layers, and the process is still under investigation.

As you are aware, mineral structures are quite different than chemical compositions. For instance, common graphite and diamonds are identical chemically, but quite different structurally. It is simple to synthesize elemental carbon in a laboratory, but not so easy to make diamonds! The covellite, bornite and chalcocite mineral identification was an interpreted result of the XRD graphs, and does not show up on this raw data. These minerals are extremely hard to synthesize, and probably impossible to heterogeneously mix at a micron level and cleanly bond to a metallic surface. Ask a chemist or metallurgist.


What is obvious from the elemental analysis is that this is not a copper oxide patina, therefore this piece was not cooked at high heat to create a crusty black patina. And since it was not oxidized and contained no sulphates, it was not created with liver of sulphur. And since no traces of gold or silver were found, it's not a niello sulphide alloy.

So what I've "proved" is that this patina is consistent with a natural "water patina" composed of natural sulphide and chalcopyrite minerals, and not a cure fake. That's all.

If the piece doesn't look Shang or Zhou, then possibly it's a later dynasty copy - but it most certainly wasn't whipped up last week and buried in a pile of cow dung and urine in the back yard.

Cheers

Doug & Moyra

Dear Doug and dear Moyra,

Let me recap because I am slow...

After all this, what you can tell us is that you can tell nothing about this bronze age.

I am sorry but this bronze really shows artificially quick-made patina. it IS a cure fake and it shows all evidence of a very recent copy (30 years more or less).

This piece can't possibly be a later Dynasty copy, simply because later Dynasty copies are documented and would show evidence of age (natural patina).

Above all testing archaic bronze requires experience: study of archaic bronze characteristics and also modern bronzes characteristics...how would you interpret your result without that?

Personally I would advice to get to a reputable lab with experience in antique testing...this one of them...

antiqueauthentification.com

Pipane

Radiocarbon/C14 dating will not work on a metal object, as it is designed to measure the amount of radiocarbon remaining in organic (i.e. once living) objects.

There are no good ways to reliably date metals. Dating of your sculpture is more likely to be done on the basis of art historical features by an expert in the field who will be able to narrow the range of dates based on the style of the piece.
Analysis of the metal can be undertaken to determine the exact chemical makeup of the bronze - e.g. amounts of tin, copper, and other components, such as arsenic - to help to establish the authenticity of the piece and possibly establish sources of the metal used to cast the piece. The copper can also be analyzed to determine production techniques, which can also help to establish authenticity. Both chemical and production analysis can occasionally provide a ball-park figure for dating, but nothing exact.

Bear in mind that all of the analytical techniques mentioned, with the exception of simple visual examination by a trained expert, are destructive - they will need to obtain a sample of the sculpture for testing. Such testing is also quite expensive.

If you are interested, I suggest you contact a museum in your area that features similar objects for more information or contact one of the larger auction houses, such as Christie's or Sotheby's. They may be able to put you in touch with a lab willing to take commissions from private citizens.

Pipane:

I understand that you believe that this piece is a fake, and that patina looks wrong. That's fine. You, and others on this board, are experienced collectors and are freely sharing your expertise in an open forum, and that is a wonderful thing. You are entitled to your expert opinion. And I also agree with you that 20 true experts will always be able to properly authenticate "good"
pieces - i.e. pieces that are well preserved, good provenance, well documented similar examples,
no style inconsistencies, extensive corroborative scientific test results, etc. Unfortunately,
a significant percentage of truly authentic artifacts do not fall into this ideal category,
and are mixed in a great pool of fakes. Does that mean that we should just ignore all of them?

If I had purchased this piece from a Beijing dealer on eBay, I would never have gone to all the trouble of having the patina tested. I would know that the probability of this being authentic was virtually zero. For lots of legal and economic reasons, there are probably no authentic ancient Chinese bronze ritual vessels being sold on eBay from China based dealers. But I didn't purchase this piece from a China dealer. I bought it from a trusted Japanese dealer who found it in an obscure private Japanese collection. That doesn't guarantee anything, but that simply improves the odds that this piece, whatever it is, might actually be an authentic "something".

When I received this piece, I spent a lot of time looking at the construction and corrosion. We don't have many bronzes, but we do have many authentic metalware pieces such as cloisonne and Canton Enamel. Like everyone else, sometimes we have accidentally purchased fake pieces only to discover the trickery once we have the pieces in
our hands. We have seen examples of fake patinas close up, and were struck by just how different this piece was from the usual junk. In fact, if you go to the internet and look on eBay you can see maybe 50 fake Jue cups from China. Not one will look anything like this piece. Not one has a black patina. Why? Because everyone "expects" to see cuprite, malachite and azurite on "authentic" examples. For the most part, authentic examples do NOT have black patinas, so why would a faker go to all the trouble of copying something that nobody believes? And in an odd small size?

Our curiosity was raised when we visited the San Antonio Museum of Art, and saw a black patina Jue
cup on display. We noticed that the black patina on that piece was very similar to what was on our piece. So we asked the question - how can one create a fake black patina? And that's how all this started. No person has yet explained how a convincing coherent black patina like this can be artificially created. From our research, we know how convincing looking "black patinas" could be artificially created, but the tests done on this piece prove that none of those easy and common methods were used on this cup.

For a very modest $85.00 for two hours of lab time, we had the opportunity to examine the corrosion products in a world class laboratory with an expert PhD minerologist. The analysis of these corrosion products shows that they are consistent with authentic archeological examples. We will email anyone interested the test results and they can look at them. Please do. If anyone can scientifically explain how a patina like this can be artificially created, even in a laboratory, please share this valuable
information. I'm very willing to change my conclusions with scientific evidence.

So, we bought an interesting piece, inexpensively, from a reputable dealer, that I believe has a high probability of being very old. Good enough. You are correct that additional tests could marginally increase that probability, but no number of tests will ever prove with 100% certainty that this is X years old. And why bother to spend large amounts of money on a piece that will never be worth that much? We're not talking about a bronze head from the Summer Palace here. :)

Cheers

Hello all.

In the interest in fairness, I'd like to tell all of you following this thread that I have submitted the results of the chemical testing to microscopy experts on another science board, and the consensus opinion on this board is that the test results are inconclusive. The only way to be certain is to formally cut out a cross section of the metal and submit it for formal metallurgical examination, but that's just too expensive. I want to thank everyone who shared their opinions on this subject.

Doug

This is the only page I can come across that talks about the subject of how to tell if a "jue" is a reproduction or not. what do you all think of this?

Hi Pipane,
I'm reading this thread because i'm trying to work out the best way to test a lost wax bronze statuette of a chimera that i own. It's in the Warring states style, is exquisitely made, ticks all the boxes described in this thread for not being an obvious fake. So i want to know what it is, with certainty! Because it's a lost wax casting, it has tiny remnants of clay inside. I'm wondering about getting the clay dated, as this wouldn't be too damaging to the object. Any idea what technique or whether this is possible? It also has a couple of small crude patches that have a different patina from the rest of it. Thanks for any help you can give...

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