A block splitting tool having a splitting blade that is formed by edges of a plurality of smaller splitter segments. The splitter segments are arranged in a side-by-side relation such that the edges form a substantially continuous blade that is generally corrugated or jagged. The splitter segments may be operatively connected to a suitable support that, in turn, is attached to a block splitting machine. When the splitting blade of the tool engages and splits a block, the edges of the splitter segments form a plurality of fracture zones that are angled with respect to each other, which results in roughened facings on the newly cleaved smaller blocks. In a preferred embodiment, the splitter segments are removably attached to a support plate, so that they may be repositioned, replaced, and/or repaired.