I think I already showed this one on the forum, but it's a small (ceremonial ?) axe from the Congo (Tshokwe).
The blade is made from aluminium with some engravings on it.
Iron was easily obtainable in these regions, but material like copper, aluminium, etc.... was foreign, thus expensive. Someone wanting to show his wealth did so by using these metals.
You also see it on some other African artwork, especially from the Congo. Copper nails were added to a statue to enhance its importance.
I'll show some better pics of the axe this evening.