Hi Danielle
From the
style and from the name of the caliph Al Mustansir (623-640 H/ 1226-1242 AD) that I can read on the
reverse I would guess that it is a fractional dirhem of one of three
Ayyubid sultans, Al Kamil 615-635 H/ 1218-1237 AD), Al Adil II (635-637 H/ 1237-1239 AD) or Al Salih Ayyub (637-647 H/ 1239-1249 AD).
If you post the other
side of the coin I should be able to tell you which of these it might be.
Best wishes
Alan