This is a Native American knife and sheath from the mid 1700’s, likely from the Lenape tribe in the state of New Jersey. It is made of an iron blade, and including the sheath made with with hide, wood, metal cones, dyes, horsehair, and porcupine quills. In the sheath it measures around 1″ thick at the thickest point x 3.4″ wide x 16.5″ long. For source and more details, click here.
Image from: http://www.nmai.si.edu/searchcollections/item.aspx?irn=43927