Thank you all for your replies and opinions! There is another interesting theory from Kirill Rivkin (I hope that he doesn't mind me quoting his message
):
"The decoration of the hilt is undoubtfully Balkan. The blade is of turkish, and as was noted, likely of Trabzonian origin. The crescents on the blade point to the end of XIXth century or early XXth century, the fullering is somewhat unusual for Trabzon pieces. Balkan kindjals often come in awfully different sizes, sometimes related to the national preferences, but often simply determined by the blade they've got their hands on."