Not sure about that. Leather pouches usually give them that soft green crud.
Seeing how they've almost completely patinated with silver oxide my guess is a consistently warm atmosphere and/or decades inside some old school paper envelope(s) of some sort.
I've handled dozens of black coins still in leather holders. They do not always have any green crud. The tanning process leaves sulfur compounds behind which leads to the terminal black toning. The "green crud" seems to be from the breakdown of the leather not simply the presence of the leather.
I'm not disagreeing that leather itself is a plausible cause, but so is extended time inside an old school paper envelope(s). You specifically mentioned a leather pouch, which are usually unfinished or differently finished on the inside- and in my experience at least, tend to generate the green gooey stuff over time from the tanning agents- so while they might indeed eventually turn black, there should also be remnants of said crud as well imo unless the coins already had some layer of patina before being placed in the pouch.
Sure. You could get to a similar state from a number of different high sulfur environments. But, in my experience, that thick of a layer is usually leather. I can't recall a paper envelope that yielded such a crusty result. But you could be right.
Comments
Okay! I'm sorry, I misunderstood as the coins and thread kept weaving around.
In honor of the memory of Cpl. Michael E. Thompson
I would absolutely leave the 1917 Walker alone, i think it’s kinda cool
As for the Peace dollar i believe it’s a waste of time and money…
But it's "natural toning"....> @telephoto1 said:
Sure. You could get to a similar state from a number of different high sulfur environments. But, in my experience, that thick of a layer is usually leather. I can't recall a paper envelope that yielded such a crusty result. But you could be right.
"Black is beautiful" on my 1995 Impala SS, not on coins.
IMHOP
Pete
Thank you for posting that.