Around 0.84 g, 15.5mm
On one side I see the sign of Crimean Khanate (similar to the letter m) and (possibly) ضرب في
باغجه سراي (struck in Bakhchysarai), although I am sure only about the first part of the phrase ("struck in"). Possibly on the bottom a part of the date is visible and possibly it contains ١ (1) and ends with ٧ (7).
On the other side of the coin the only word I can read is كراى (Giray). Before it I see something like ط هن (T hn; I might be wrong about this) and above it ن again.
I don't see any Crimean khan named "Tahn" (or with even remotely similar name) on the catalogue or in the list of Crimean khans in Wikipedia.
Any ideas would be appreciated.