This pebble looks like it was hydraulically smoothed. It is very dark gray or black on the side that was exposed. It is 3.5 inches long, 1.5 inches at the widest part and weighs 5 ounces. It can be scratched easily with a nail file. The underside (that was in the ground when found) looks slightly lighter in color (medium gray). Cannot determine if it would be considered granular or not - if so, it it very fine-grained. Looking for possible ID. Thank you.
