Last month I purchased a two hundred year old Othomanoc knife from a dealer in tha Athens center . I felt in love with this handmade knife and the engraved decoration and the soft corrosion .The surface is plated with silver and other silver parts are applied .
It has a projection in the back for application in a belt probably , it also has two crystals applied in the decoration of the case of the knife , the case has the most decoration and has wood in the inside for better restrain of the blade .
The blade has some Arab letters engraved that I don’t know what they mean….. yet , the blade from what I see it has been used a lot mainly for stabbing people and that you can understand it from the shape of the blade(its pointy and the shape of the case keeps it that way) and it’s only natural because in that period the Greek revolution was taking place.
The beautiful decoration indicates that it belonged to a superior soldier with some kind of higher degree , or it could be a gift for bravery. 
I'm going to make some cleaning prosigures in order to Highlight the decoration and the shining of the silver , it will be as good as new and ready for use hahaha.
You should have it appraised. You may have a historical artifact there.
Very cool knife!