Abstract: An irregular, tessellated building unit comprises x primary elements, wherein x is an integer equal to or greater than 1. The primary element is a rotational tessellation having a plural pairs of sides extending in a generally radial direction from plural vertices, respectively. In each pair, the two sides are rotationally spaced by an angle that is divided evenly into 360 degrees. Preferably, all of the sides are irregularly shaped, but one or more sides could be wholly or partially straight. Optionally, spacers are provided on the sides of each unit. A wide variety of units may be constructed having different numbers and arrangements of primary elements. As all the units are combinations of primary elements, they readily mate with each other. A surface covering comprises a multiplicity of units assembled to form a continuous surface without overlap between units and without substantial gaps between units. A structure, such as a wall or column can be formed of building units of the invention.

Abstract: A method of making a wall block and a mold box therefore. The wall block design maximizes the use of the mold box. The method produces wall blocks having a large surface area front face compared to the front face size of prior art blocks. The blocks have about one third more front surface area. This results in faster construction of walls and a faster construction sequence. The method of making the blocks makes efficient use of mold space and material, resulting in higher production yields and/or higher total daily production square footage.