agate appears to present a late afternoon forest scene. Can you see it? The trees along the bottom in a shallow valley, something dark in the background—perhaps a mountain range—and the the sky light gray and hazy as the sun sets on the left. Or something like that. Maybe the dark top is storm clouds gathering. Anyway, it's all natural; look and see what you can make of it, kind of like seeing pictures in clouds, but more permanent. This was a piece of agate that my uncle gave to my mom; I'm not sure where my uncle got it, but some people spend a considerable amount of time wandering the plains “hunting” for rocks like this. Maybe it's mostly a western thing. Many of the same people also hunt for arrowheads, which are plentiful (or used to be) in certain areas where native tribes hunted or lived. Oh, and just so you know, there's also an Agate Fossil Beds National Monument in Nebraska, near Scottsbluff on the western end of the state. It might make an interesting stop on your next cross-country drive.