Abstract: Irregular surfaced slabs of stone are split into blocks of selected width by an apparatus having an upright frame mounted upon a base and with spaced vertical columns connected to opposed upper and lower vertically reciprocal carriages carrying rows of individual power rams each connected to chisels for selected vertical reciprocation relative to the carriage and into engagement with a stone surface. The chisel rams lock into engagement and carriage rams within the columns and on the base move the upper and lower carriages toward each other to split the stone therebetween. Separate hydraulic power units for each carriage and the chisels carried thereon are connected via electrical circuits to a central unit for regulating operation of the apparatus. An upper hydraulic power fluid unit is mounted to the upper carriage for movement therewith and includes a motor driving power fluid pumps and having a reservoir integral with the upper carriage.