Bought the lefthand one last week. Other I've had for almost 20 years. I think they are both silver ga-den type 1 tangka coins. I know some Tibetan coins are dated in the Tibetan script, either as numbers or with spelled-out dates. But I think the characters on the top side are just an inscription, shared identically by many other types of tangka coins. I think I have deduced which symbols are which on the bottom left image: Center--Lotus Peremiter, clockwise from 12:00 position, the 8 auspicious Buddhist symbols (Ashtamangala): 1) Parasol 2) Two Golden Fish 3) Vase 4) Lotus 5) Conch 6) Endless Knot 7) Victory Banner 8) Wheel of Law Other tangka coins have the symbols in different orders. My Krause guide does not have all the variants pictured. There appear to be many subtle variations. I checked on Numista, but am not sure how to interpret some of the descriptions. I wonder if it might be Y#C13.1 as the "spokes" on the wheel of dharma extend out to the curved "octagon" on the left one. But I don't know if other varieties also have that trait. Any advice on how to find the date and variety of these would be most welcome!
Left coin looks like ND(1912) Y-F13.3 Ebay item#172341229961 Right coin looks like ca. 1880 Y-B13.1 Ebay item#183790128707 both coins on Ebay are slabbed PCGS. Hope this helps you ???
Thanks for both replies! I had not seen the Rhodes paper before. If I can make out all the details correctly, my best guess is that the left one is type F(vii) (1912-1918) and the right one is type B(i) (1880-1894) It sounds as if all the detail changes were an anti-counterfeiting measure, so there must have been significant numbers of contemporary counterfeits.
