Possible Meiji Era silver medal

Can anybody identify this? I found it being sold for 18,000 yen at a coin shop in Nakano. I speak fairly good Japanese and talked with the shop owner, he honestly didn't really seem to know what it was. I'm thinking it's possibly a variation of a Meiji Industrial Exposition Medal, and I'm fairly sure it's made out of silver, at least partially. It's pretty large, double the diameter of a 1 yen silver coin.