Guaranteed authentic antique jambia dagger. Islamic, probably indo-arab or indo-persian. 
Very similar example, most definitely made by same maker, is in collection of new york metropolitan museum of art (please see last picture for reference). 
Truly jewelry quality - indication of wealth and high social status. 
Exceptional quality silver grip and sheath (scabbard) - all hand chased and hand engraved, meticulous attention to small details.
One natural rose-cut diamond at the top of pommel (approximately 6.5 mm diameter real diamond, electronically tested).
Stunning damascus wootz blade.
Precious "black wootz" steel (also known as "kara taban" or "kara kharassan" ), intensive high contrast watered pattern - would benefit from professional etching and polishing. 
Blade shows some minor forging flaws. 
Wooden core inside silver mounted scabbard.
  size:
11 5/8 in. (29.6 cm) long in sheath (straight line).   
11 3/8 in. (28.9 cm) long out of sheath.
Blade is about 7 13/16 in. (19.8 cm) long.
  condition: 
Very good original antique condition, shows light normal honest wear and charming indication of age. 
Expected handling marks, dents and scratches to silver.
Minor forging flaws on blade.
 Exceptional quality precious example - pictures don't do justice!