Abstract: The invention is to make a mold that will make a square 12×8×12 block that when split makes a full 6×8×12 and a half block that will be used in a construction system based on the combined use of split-face mortar less blocks designed to lock together. There are two basic blocks, the full, and half block, with which any desirable structure can be built. The full block has protruding ears and grooves. The half block also has protruding ears and grooves. There are standard measurements between groove face in all blocks and standard measurements between ears in the full block which correspond to the measurement of the groove faces. This provides for a wide array of interlocking positions.