Idolenz
How have you found it? I am still searching for a good coat of arms book but most 18th-19th century books I found are missing graphical aids.
It looks to be this one, judging by the shape of the crown. But, a catalogue like ucoin had more variety and more types, but they also lacked photos. N#316562
I found it mostly by accident. I was researching something about the Polish Piasty dynasty, and stumbled upon a portrait of Christian of Liegnitz-Brieg (he was one of the last members of the Piast dynasty). And, as it turned out, his portrait also included the coat of arms of the duchy, which was almost exactly the same one as on the coin. Here is the portrait.
