This is an English silver knife, in which both the blade and the handle are silver. The piece measures 8 and 1/2 inches long, and is in excellent condition. It's hallmarks are visible and declare it to be English Sterling, made in Glasgow, in the year 1843 (sovereign's head is visible), and the maker's marks are "RG." This would be an excellent addition to any collection of early Victorian silver; it also would make a great letter opener.
Victorian Silver, Knife, Glasgow, 1843