Hi Jason

One medal with William III on one side and Mary II on the other?

I did find two different medals with the same portraits ...

Price realized: 95 GBP   (Approx. 132 USD / 110 EUR)   

British Historical Medals from Various Properties

William III, a silver medalet, undated, bust right, rev. non devio, radiate sun, 22mm, 2.97g (MI I, 695/92); Mary II, a copper medalet, undated, bust right, rev. ex candore decvs, rose, 5.61g (MI I, 695/93) [2]. First with scratch in front of face and minor flan flaws otherwise very fine, second fine £40-£50

Hi Jason --

It is a well-know pattern (i.e., prototype of a) farthing in silver, or a modern reproduction of one. I can't tell from your picture if it is genuine or a reproduction.

Our page on these coins appears at this link. The page has ID and value info:

https://coinquest.com/cgi-bin/cq/coins.pl?coin=15913

Further, the one in the picture here sold for $350 US dollars in a 2017 auction. Compare the details of your coin to this one. Here is the description that accompanied the 2017 auction:

Ira & Larry Goldberg Coins & Collectibles > Auction 98    Auction date: 6 June 2017
Lot number: 2896

Price realized: 350 USD   (Approx. 311 EUR / 271 GBP / 337 CHF) 
Lot description:
Great Britain. Pattern Farthing in silver or official farthing sized medalet, Undated. MI-691,81 (pl.LXXV,9); Montagu 15. Edge plain. 23 mm. William and Mary, 1689-1694. Tribute to William. Obverse portrait of king right by John Roettier, legend GVLIELMVS III DEI GRATIA. Reverse, Mary right, MARIA II DEI GRATIA. A stunning piece in mint state with deep pastel blue toning. Rarely seen in this grade. NGC graded MS-62. WINGS. Estimate Value $200 - 250