"a manila envelope" - or cardboard 2x2, a coin album, original packaging from the mint - basically any and all paper and or cardboard products, because they all contain high concentrations of sulfur. (Other than those of archival quality of course but those are few and far between.)
If you go to acsearch.info and do a search on "Boscoreale", you will see numerous examples of Roman Aurei with the red-purple toning characteristic of coins found in a hoard at Boscoreale. It is distinctive enough to have earned it's own designation in Roman numismatics.
Another way I like to work around linking an ebay item is simply taking a shot at the whole page showing the item that ended. A nice looking coin. I always thought blues and reds on old gold coins were interesting.
Here are a few more toned gold in my collection. These won't be for sell anytime soon. All are PCGS straight graded, and it has taken years to get the set to this point.
Gorgeous. I love toned gold. Haven't had any with really colorful toning, but I do like contrasting darker gold or orangey toning. I knew @jwitten would show up here.
I love toned gold too . . . as much as I'd like to keep them, quite a few have passed through my hands to customers. Here's a sampling . . .
That 1906 quarter-eagle makes my heart beat a little faster. (Not to mention the impressive array of @jwitten's tribe above...)
Yes it is, but that's because ebay removes all closed auctions after a short time. But pics of the coin in that link are posted elsewhere in this thread.
That bust is from the dead King Carlos IV 1788-1808. No one in Colombia/ Nuevo Reinos Mint knew what Fernando VII looked like, so they used the old Kings portrait. Maybe, during 1808-13 (when Spain was under French occupation) but by 1819 a ship easily could have sailed too Colombia with new Rulers portrait.
I'm just going by memory but I'm think they only used that old bust on coins for 1 year. And if I recall correctly, it was more of a timing issue than anything else - they had to get the new coins out and there was no time to make all new dies. And besides, pretty sure the dies all came from Spain, they were not made in the colonies.
I have one from Popayan Mint (1819) with old Carlos IV bust/ and one from NR mint 1812/11 Carlos IV. For Colombian Mints they used the old Kings bust till Independence. In Peru/ they used the "Imaginary Bust) for 1808-10 then the actual Ferdinand bust from then to War of Independence. Chile/ had the so called Admiral Bust/1809-10/ then reverted back to Carlos IV bust. Seemed/ back in Spain no one was up to date/ maybe that is why they lost their New World Empire.