This thick-skinned, beige mushroom, rounded but flattened, 3/4 to 1-5/8 inches across, is not a true puffball, but an earthball. The generic name, Scleroderma, is also that of a skin disease. It refers to the mushroom's warty surface.
When you cut this earthball open, it begins white, but soon turns purplish-black, and it's always hard. When mature, the powdery spores become blackish-brown.