The back of the coin/medal.

A much larger version can be viewed here -

The face of the coin has a crest (Royal?) and an inscription which is hard to discern. I can make out the word Empress. Above the crest is what looks like a Griffin. The back on the coin has what looks like a female head facing left - not unlike Queen Victoria, there's no distinct sign of a crown and the hair part covered by a scarf.
May be able to make out a tiara/crown under the scarf/veil.

I can plainly see the word Victoria opposite the face - similar to a coin. I cannot see a date.

It MAY be a Sunday School Jubilee Medal minted in 1887 to commemorate the Jubilee of H M Victoria Queen & Empress. This medal was also the same diameter.

Or it might be a ......? to be amended.