That was real abalone at one time, cut and inlaid by hand. A long long time ago. Before the days of ready made headstock overlays.
Here it is, 97 years ago on an F5 mandolin, "the finest abalone in the world" per Gibson, and inlaid by hand.
Kind of bears out my "devolution of the species" theory. Are we better that we were 100 years ago? Are guitars better?
Answer is yes and no, but we hadn't invented plastic yet...