I love a good mystery! The photo above is just that. I found the rock yesterday in the creek just below our house during our dog-adventure which we take every day. While the image appears convex, it is the opposite: concave. The chunk of rock appears at one time to have been hot, maybe molten. Measurements of the solidly embedded specimen--or perhaps I should say the mold made by the once solidly embedded specimen: about three inches long, an inch and a half at the widest part (on the left); unusual shiny metallic veins that glint in the sun. The rock is more basalt-like than regular sandstone or limestone. It measures about six inches across. Pretty heavy, too, having carried it up from the creek-bottom..
Do I have a fossil? A trilobyte of some kind? A visitor from outer space? Ideas please!