action14 wrote:
Hi Jim
The one side is definitely black. The other picture is where we believe is the origin of the triangle stone. As you can see it has a white stone surface and is black where there used to be a void in the shale. It's visibly white edge is what caught my eye when searching the area.
Jon
Hi,
I'm kinda new in this form, but have 36 years of field collecting and mineralogy experience. The triangle rock is of an igneous origin. The possible souce shown in the photo very much matches the triangle rock with the consistency of what appears to be a type of manganese deposition on a fissure, which is a weakness in the rock, which would be an easy point for the stone to be split off the face of the rock wall. The black is definitley no soot or growth - it is mineral deposition in a fracture in the rock.