Silver Coins. Why Sometimes Shiny And Sometimes Toned?

Ricky, do NOT clean the Cuba coin. The toning is perfectly understandable and acceptable. Why it toned would take a long discussion, but it is preferable to leave it in its toned condition than to dip it in a silver cleaner.
Second, ebay does not allow the sale of coins from Cuba under any circumstance because of the embargo, unless you can sneak it through with an oblique listing.
Other online auction sites do not have such restrictions. I have seen some on HiBid.com, but not a great number. There are some on other sales sites but they are ones known for having many fakes and counterfeits.
I would like to get a Cuba peso coin such as the following but they are not easy to come by here in the US.
https://en.numista.com/catalogue/pieces9263.html

Wow, lots of questions in this post, let's see if we can break it down.


The coins have had different histories, and been exposed to different environments.

The chemical that causes silver to turn black is sulfur. Sulfur is present in many things: industrial air pollution, cigarette smoke, human sweat and saliva, cooking fumes from garlic, onions and eggs, and even certain kinds of rubber and cardboard. A silver coin left exposed to these things will turn black; a silver coin protected from such things will stay shiny and silvery.


Coins can get "ugly toning". But most collectors would agree, that this specific toning is not "ugly" and should not be removed. As noted above, toning of silver coins is perfectly "natural".


It is indeed because of the embargo. Rather, it is because of ebay's robotic (and most would say idiotic) interpretation of the embargo.

ebay has placed a blanket ban on the sale of any artifact from Cuba. This ban is mostly enforced through ebay's listing-checking bots. Anyone putting "Cuba" in the listing or description, will find their listing will be automatically blocked.

Some people try to get around the ban by listing Cuban coins under a pseudonym like "Kuba", "South Florida" or "the big island west of Haiti". The bots won't be triggered by such listings, but a search on ebay for "Cuba" won't find them either. However, if somebody manually reports such a listing to ebay, that ebay seller is likely to get banned from ebay for deliberately trying to avoid the embargo.

Yes, it is "stupid" and illogical that coins struck by the pro-USA pre-Castro regime in Cuba (many of which were actually struck in US mints) are also banned. It is also irrational and unfair that coin sellers outside of the USA (from countries which do not have a diplomatic spat against Cuba) are likewise blocked from selling their coins on ebay. But, ebay's house, ebay's rules. If you want to buy or sell Cuban coins, you'll have to go somewhere else.

Thank you everybody for your kind answers! It has all been most enlightening to me. Thank you.

'Don't clean your coins' that's what I always hear.

Then when I send in my beautiful toned coin in for grading, the grading company asks if I want to 'conserve' my coin.

When collectors clean coins it's a no no but when grading companies clean coins is called conservation. Hmm.

Toning has to do with exposure to the atmosphere, elements, levels of preservation utilized or ignored. Storage, sunlight, moisture, etc. etc.
Some coins are cleaned, some are spoiled, some are polished.
Some collectors don't agree about their own coins, so a natural toning might be cleaned, dipped or shined up. And that can ruin the piece in the eyes of many. My idea is that if you have a crud looking coin, and you clean or polish it, you just exchange one undesired look for maybe another undesired look.