An engraving machine for engraving building material articles comprises a working plane on which, in use, at least one building material article rests, and defining a working area having a predetermined width, an engraving device facing the working plane and equipped with at least one reservoir for containing an abrasive particulate material, and an array of nozzles for delivering the abrasive particulate material configured for making a predetermined engraving path on the article, and moving means configured to determine a relative sliding between the working plane and the engraving device along a movement direction transverse to the predetermined width. The nozzles of the array are arranged in succession along a direction transverse to the movement direction to fully cover said predetermined width. A control unit is and configured to drive associated nozzles independently of each other.

The invention provides a block splitter assembly comprising first lower and second upper opposed splitter blade assemblies. The splitter blade assemblies have a splitting blade and two or more first forming blades. One forming blade is disposed to the right of and one forming blade is disposed to the left of the first splitting blade. The forming blades have forming edges. The splitting blade has a splitting edge that is straight, and the splitting blade has a greater maximum vertical dimension than the maximum vertical dimension of the forming blades. The splitting edge of the first splitting blade is opposed to the splitting edge of the second splitting blade.

A masonry block that is produced from a workpiece that is split in a block splitting assembly which uses any of a variety of projections to supplement or replace the action of the splitting blade in splitting and dressing the workpiece. The resulting masonry block has features that provide the masonry block with a weathered appearance.