20 cash chinese coin Tai-Ching-Ti-Kuo 1906, which province?

20 cash chinese coin Tai-Ching-Ti-Kuo 1906, which province? 17.1g and 35.2mm

Kiangsu
https://en.numista.com/catalogue/pieces9281.html

Thanks a lot!
what is about this 10 cash TCTK unearthed coin? 30 mm and 11.8 g. It is close to Y#20t.1

patina looks odd, examine edge of the coin with a loop, if edge is smooth with almost no sign of wears, it's probably a modern copy.

yes, patina is strange, it looks like this coin was in dirty baked in the oven for a hundred years. As a result, it was hard to clean this coin. I use table vinegar (7 to 9 %, acid) that dissolve patina including ceramic-like patina and stone-like patina (I use a mechanical cleaning right away after the acid action, etc.) but this acid does not dissolve metals, but zinc coins and aluminum coins. As a result, after the cleaning only metal is present but with many rough surfaces because any spoilted surfaces were dissolved. This relates to the edge as well, the surface of the edge is also rough like the other surfaces of the coin. However, the coin looks like in an unchanged condition.

So, modern coins are cleaned for several days with this acid but handred year coins are cleaned for several months or even years. I spent several month for this coin , sevral cycles such as acid-alcalin-mechanical action.

Your second coin does not look genuine to me, and it is actually of a ficticious type.

I think a good way of determining fakes is by looking at the Manchu characters--they should be very thin and precise, but your example has very thick characters (and rather long denticles):


(Yours / Genuine 10 Cash / Genuine 20 Cash--your weight suggests a 20 Cash piece, but your diameter is in-between the two denominations, closer to a 10 Cash piece)

With that being said, the centre is definitely from Szechuan; however, while the Chinese characters on the reverse say Guangxu, the Manchu characters on the obverse say Xuantong (and the genuine examples I took for the above pictures were from Xuantong e)xamples from the Szechuan mint).

Now, I have seen the reverse situation happen (the Chinese characters say Xuantong while the Manchu characters say Guangxu), which I imagine came from the mint works not fully understanding Manchu. But considering how thick those Manchu characters are, there would be a more likely chance of this being a counterfeit rather than a rare mule.

OK, thank You very much. I do not know , too, that it is a genuine coin or modern counterfeit.
However, let discuss why I think that it is a genuine coin as well.

First of all, I have to state that this my coin was in the ceramics-like patina. As a result, such patina can be formed only for long time under earth.

Second, the stempel of the coin is deep enough, deeper than the stempels of these two genuine coins You have shown. The deeper stempel is a plus to the opinion that it is a genuine coin. Also, the weight is 11.8 g for this 30 mm coinin diameter because it is a thick coin, 3.6-3.65 mm!!!

You have to know something about the prodution technology of milled coinage. First of all, I know that in the 1980s, in China some buzynessmen have bought old setups (100 year tools) for milled coinage prodution to produce counterfeit chinese coins. However, any old tools for the milled coinage production assume production of ~10,000 milled coins with one stempel before it is crashed (one modern stempel is for from 250,000 coins because any modern stempel is not so deep). So, assume that my coin was produced only with one stempel (in general, a matrix is produced before, with which already several the same stempels can be produced, each of them is for production of only ~ 10,000 coins!!!) . The quastion is where there are the other at least 10,000 coins because I have only one single unearthed coin in my collection? If my coin was produced with some modern tools (in assumption that was used only one single modern stempel), there should exist at least ~250,000 such coins!!! However, nobody has seen my coin before and there are no other such coins. Why? Counterfeit coins mean that there are a lot of the same counterfeit coins, significantly more than the same genuine coins.

Note that 100 year ago, for the production of the milled coinage there are should be produced at least three the same stampels every day to produce milled coinage during all 24 hours a day (the old tools can produce only one coin per second!!!). However, any experienced person in China knows that ten cash coins in China were produced with multi-million items every year because they are the most popular coins. This means that from 1,000 the same stempels a year should be produced for the multi-million milled coinage production!!!

Quote: "vvvzzz"​First of all, I have to state that this my coin was in the ceramics-like patina. As a result, such patina can be formed only for long time under earth.

​I have spoken to you about the "unearthed" condition before, and this statement is not true. This condition/patina can be faked as a way of trying to hide the finer details which, when cleaned, are shown to be obviously incorrect. Counterfeiters can be smart, in this regards, and I have seen it many times before.

And regarding how many coins a minting process produces: I imagine this is irrelevant to counterfeiters--they can do whatever they want. However, there very well could be thousands of replicas identical to yours, and the reason we do not see them is because there are (at least) billions of counterfeit types out there (meaning the odds of finding those counterfeits coins are slim), and people are more worried about documenting the genuine coins. If there is no documentation about a coin that looks like a counterfeit, odds are, it is a counterfeit and not some rare variety.

As well, the thickness is another indication that your coin is not genuine--that is abnormally thick, compared to the originals.

With all that being said, we now have an Exonumia section, which has its own section for Replicas. With this being a ficticious type--if you would like to add it to Numista--you will have to do so following this link.

I am not worrying to add this my coin even it will be treated here at the Numista catalog as a counterfeit coin. Indeed, even I am not sure that it is a genuine coin.

I just added it, so, You can add the chinese symbols here https://en.numista.com/catalogue/exonumia287732.html

Note that Patina even of unearthed coins does not disturb to see all details of the coin. I clean all coins in my hands, new coins and old coins, europen, americal, chines, japanese, etc. because it is necessary to clean old coins one time per half hundred year, one hundred years, two hundred years. For instnce theer are many Austrian and prussian bronze coins with dirty metal. This means that after cleaning with an acid many dirty areas (which after hundred years are already like ceramics but not pure metal) will be dissolved by the acis. As a result, it is said that cleaned coins are 30% cheaper than uncleaned coins before cleaning. So, in Russia now not only unearthed coins but also some unearcthed icons and unearthed millitary things are cleaned by an acid, in general they are brass things. Indeed, some mechanical polishing is used after the cleaning to delete many spoilt areas that actually exist in the cas of the unearthed things.

I added more information to the page, and approved it. Thank you.

It looks like there needs to be a bit of rearranging with the Chinese replicas, so I will get on that.

And I would be weary about cleaning any coins (with products other than 100% pure acetone, at least)--many products strip the original surfaces or leave pitting marks, which decreases the value. Even with vinigar and copper, while the vinigar should only react with oxidized copper, that oxidization effects the surface copper (meaning the original surfaces). And I imagine that is why the pictured examples look stripped of their original surfaces--they look pink rather than red (although being replicas could have something to do with that as well).

The pink comes from the surface that is now thanks to the aggressive acid bath full of craters like a sponge with reflects ans scatters the light so it appears pinkish rather than copper red.

Treating every coin mindlessly with acid baths is the dumbest thing I've read in a long time on a Numismatic forum *uff*.
You want to passivate your finds not destroy them. If what you say is true remind me to never swap with a Russian without very thorough coin pictures.
Also you only want to get rid of brittle copper verdigris (~Cu(CH₃COO)₂·[Cu(OH)₂]₃·2H₂O) not green copper patina (a basic copper-)carbonate/sulfate/chloride/hydroxide mix) which out this we wouldn't have 2000 year old Chinese copper coins.

P.S.:
In my opinion UNmarked copies (aka FAKES) don't belong in the catalog anywhere (I don't know about contemporary counterfeits personally I don't see them much different but at least I see them in a better light then cheap Chinese massware).

Thank You very much. I will try to use acetone instead of table vinegar.

The surface of copper coins after the cleaning looks pink but not usual red because I put the coins right away in a zip-lock packet. If I will leave them on the air for one month, the surface will have the usual nice red thin-film patina!!! In the zip-lock packet without a direct contact with the air, the copper coin will be in the usual red patina only in one or two years!!!

However, my current interest is to clean coins that were unearthed on the planet Mars. Nobody knows that the main purpose of all the space expeditions to the planet Mars carried out by the NASA (USA) is to unearth marsian coins but not to find any live on the planet!!!

Quote: "vvvzzz"​However, my current interest is to clean coins that were unearthed on the planet Mars. Nobody knows that the main purpose of all the space expeditions to the planet Mars carried out by the NASA (USA) is to unearth marsian coins but not to find any live on the planet!!!

​To quote Mark Twain, "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."

The NASA is looking for any life on the planet Mars during the last several decades but unfortunately. This is stupid. They have to change their priorities to look for coins (metals) under the marcian soil instead of to look for some organic compounds that are in general complicated molecules that are destroyed by time. As soon as they unearth some coins on the planet Mars, this will be an evidence that at least one high form of life existed on the planet!!!