Abstract: An irregularly-shaped building unit includes a front surface, a rear surface opposite of the front surface, and an outer contour surface that extends generally perpendicularly from the front surface to the rear surface. The outer contour surface is irregularly shaped. A plurality of mating sides are disposed on the outer contour surface, where at least two mating sides intersect with a major axis, and at least two mating sides intersect with a minor axis. The major axis and the minor axis are generally perpendicular to each other. Each mating side is a centered rotation about the respective axis that the mating side intersects with.

Abstract: A wall block comprises an upper surface and an opposed lower surface. A front face and an opposed back face, and a first side face and an opposed second side face, are disposed between the upper surface and the lower surface. The first side face and the second side face generally extend from the front face to the back face. The block includes one or more features that define a horizontal alignment direction. The front face extends from the first side face to the second side face generally along a direction that is slanted with respect to the horizontal alignment direction.

Abstract: A surface covering comprises multiple units adapted to mate with one another and cover a surface. Each said unit comprises at least one primary rotational tessellation element that defines the sides of the unit, has an irregular configuration, includes a face having molded surface irregularities or variations therein, and has at least two pairs of irregularly shaped sides. Preferably, gaps of variable width are defined between visible edges of adjacent units in the surface covering. The surface covering has a natural appearance such that a repeating pattern is not readily apparent. A structural wall unit system is also provided.

Abstract: A corner block and a wall block system with a corner block for forming in multiple courses a wall which includes first and second visible wall portions which meet at a corner and where the corner block has a front face and at least one side surface having a texture or pattern matching the texture or pattern of a front face of a first block of the wall system.