Help Me Preserve This Bronze Coin | 1423 Joseon Tongbo

@notoriousking, you're an absolute buffoon and I think you really need to take a detention and think about what you've said.

That being said, as others have mentioned, East Asian cash coins are often prized for their lovely encrusted patinas. In some cases, the encrustations can actually increase value and desirability. It would generally be frowned upon to remove a well-established patina, such as the one below; I never get tired of showing off this lovely coin.

A Northern Song 10 cash with incredible encrustations of azurite, cuprite, and malachite!

 

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That coin is beautiful! Interesting that you mention specific mineral encrustations. I'll have to look into that topic a little more. Any suggestions on where to start? Google seems a little bit scarce on the subject... or I'm just putting in the wrong keywords. lol

 

@hotwheelsearl.......Wonderful colouring!!

 

@hotwheelsearl Awesome one! I absolutely love how the blue and green blend together on the reverse. Those blank reverses are really the perfect receptacle for those fine pieces of art created by nature... Since I collected minerals as a child, I particularly enjoy that.

I'd be interested as well if anyone has ressources on how those encrustations appear and what kind of grounds favour them. I guess it's some basic chemistry. I know some people are able to attribute some patinas to some areas of China, a bit like a roman coins collector would recognise a spanish patina.

 

I wish I knew how/why those minerals form. I suppose the base metal, copper is already pretty reactive so it’s already prone to oxidizing.

I believe that the minerals of malachite and azurite often form in conjunction; not sure about cuprite but they’re all there. This coin has probably 90% malachite 8% azurite and 1% cuprite, but why those ratios is beyond me. I’ve seen some coins with a much higher rate of azurite, and some with no malachite at all.

The problem is, with many Chinese coins, they are unprovenanced so nobody can really tell from what region/locale they were found.

patinas will certainly vary from location and often have a look unique to a specific place (ie Boscoreale patina is typically only found on those coins found in Boscoreale; Tiber patina is often found in rivers, though not necessarily always the Tiber)

 

Not saying you’re wrong, but the crystalline structure of the cuprite and azurite looks pretty good, though The Chinese can fake just about anything so

 

I am pretty sure that this specific patina is perfectly legit, even if @chinesecoins is right when he says that chinese counterfeiters are getting dangerously good at making fake patinas (and coins).

By the way, welcome on board @chinesecoins .....

 

I literally don’t understand you, can we try again?

 

@hotwheelsearl, read my last post in the Roman Republican No. 54 thread. And his right above it, if it hasn't already been deleted.