This is a nice group of scalenohedrons with elongated marcasite inclusions inside the crystals.  As was standard practice among miners in those days, it has been lightly cleaned with acid.  There are also small cleaves/ chips on the terminations, but again-- this is an OLD piece, and it is next to impossible to find *anything* from Webb City these days.

If the pictures look slightly purple on screen, be advised that it is colorless-- this is not one of the fabled Webb City purples, though incandescent light does bring out a very very slight hue that the camera seems to have picked up on and exaggerated (I had to reduce the saturation) so clearly there is a bit of whatever impurity causes that color present.