According to my research, what you are calling a darsek is actually a knife embellishment (as noted above). That's not to say that a collector could call them a darsek if they wanted to. Here's a close up of the piece. Oh and the texture around the glyphs are "pot holes" not raised.
According to the comics, Klingons have a currency called "Talons". There was a fan made minted set of coins called "K'chuk" coins that have an awfully familiar look.