They are incused. Many have responded that they have the same marks in the same places, so I'm pretty sure there are two variations. When looking at the strike head-on (not at an angle) the marks look like a mirrored reflection of the fountain spray on the pool below. I just thought it odd because I don't recall ever seeing those lines. When I looked closely, the curved lines run right through the marks, so they are not scratches made after the strike was struck. Perhaps it's like the frosted thing. When they first started stamping the strikes, the incused marks were pronounced and as they wore down the marks disappeared?