US3460.)WWII ERA US ARMY GENERAL STAFF BADGE: oh, this is an early one and you'll agree. Gem quality, so nickel made. 47mm wide and its widest points and vaulted in construction. Separately applied bronze American eagle device in center on black enamel star, green glass enameled leaves. Really a gem. No chips nor any cracks to glass enameling; on minor disruption (very small dark area) to glass on the lower green leaf at tip. Reverse has three clutch-back devices and is marked to familiar maker 'NS MEYER, NEW YORK' with this company's shield logo. EXC++++

Note that the 'G'-number markings for US insignia didn't get introduced until the 1950's so this is an early one!
The white spot on the lower star burst arm is from light reflection, not a chip in the enamel.