Stone Mace from Papua New Guinea

This is a 19 C. war mace from Papua new Guinea, with a black stone discoid   shaped head, 5 inches diameter, mounted on a 42 inches wood haft with a braided rattan sleeve.  Very good condition, good age patina on the stone and the haft . Minor chips on the stone head and age cracks on the haft. Quite a scarce item and an important addition to any weapon / tribal art collection