re: Check it out...the RAT sliced a bead
Did some contrast enhancement and sharpening in Photoshop on the two spheres that were cut into.
Sure doesn't look like there is any sort of layering or composition differences or anything, other than the dirt sitting on top. I suspect the dark streaks in the one on the left are related to the grinding, though I'm willing to be told I'm wrong.
They look quite solid. Someone suggested a squash test earlier? I don't think much would have happened, those spheres definitely don't look delicate. I bet those spheres would polish up quite nicely. The matrix seems less cohesive, more granular.