This very large Tridacna shell adze was collected by a World War II Navy construction worker (Seabee) while building an air strip on one of the Stewart Islands in Melanesia. It's been ground and polished to a nice oval shape. One side has a prominent dorsal ridge down its length. The cutting edge is rounded and was formed by beveling from one side. This adze measures 9 5/8 inches (24.5 cm) long, 3 9/16 inches (9 cm) wide and 1 13/16 inches (4.6 cm) thick.