Looks like a bronze handle with a polished central brass band and possibly a forged steel blade (pictures need to be enhanced).
Antiques are a minimum of 100 years of age...This knife looks old but almost too pristine for being buried...don't think it qualifies as an antique...
This knife has the appearance of being foreign and possibly Spanish or Mexican in origin.
It doesn't have the crudeness of a blacksmiths work...therefore it's probably from an armory.
Generally an armorer (maker of swords, knives etc) is a master craftsman and will not turn out a product or combined product that is a mismatch of quality.
The handle signify's it was cast by a craftsman but the brass band and the incised decoration is not craftsman quality workmanship.
Could be wrong, however it looks more like a replica of recent vintage.