Found this in a creek in the mountains of North Carolina.
That looks like a garnet schist. The large crystals appear to have a rhombic dodecahedral habit typical of garnet.
This rock is probably a garnet schist, possibly a garnet-mica schist. The dodecahedral shape and color of the red-brown crystals means they are most likely garnet. Because of the rock's platy texture it iss most likely a schist. Medium grade metamorphic rocks are common in all of Appalachia. And, if it's shiny at all it probably has micas in it as well as garnet. I couldn't tell from the pictures. Also the size of the crystals could tell us something interesting about the formation of the rock, but I can't tell just from looking at it.