Silver cash coin references?

Showmetheway

Came across this auction on eBay which seemed intriguing. Seller seems reputable so have tried to gain some knowledge behind it.

‘Yuan dynasty’ tian tung tong bao
4.1g, 21.9mm diameter,1.4mm thick

Despite the alarming amount of counterfeit coins from China nowadays, there have been apparently rare examples of cash coinage being struck in precious metals. I unfortunately don’t have access to a David Hartill reference book, so any expertise on such coins would be adored here. Seemed just too good to be true finding a rare AUTHENTIC coin on eBay?

harasha

This cash coin just does not look right, but I will let others weigh in.
In my opinion, it resembles a cash coin of a Yuan rebel, Zhang Shicheng. His coins referred to his reign as Tian You. The legend would read, Tian You tong bao. The character at 6:00 does not appear to be tung. It more closely resembles You, in my opinion. Anyway, I do not think there was any reign known as Tian Tung.
See Hartill 19.134
I doubt that the coin is silver.

Showmetheway

@harasha
Thank you for commenting on this. There was only one other coin that someone attributed as Tian Tung Tong Bao and that was a copper version of this coin on either the coincommunity or cointalk forums lol. I’ve tried to find cash coin amulet or charm publications but seems Hartill didn’t delve into that area much…