Patent ID: 7393155

Claim:
A building unit having at least one face comprising, a first side extending in a generally radial direction relative to a first vertex, said first side being irregularly shaped; a second side extending in a generally radial direction relative to the first vertex, said second side having substantially the same length as said first side, being substantially a rotational image of said first side and being rotationally spaced from said first side by a first angle of 360 degrees divided by n, where n is an integer greater than or equal to 3; a third side extending in a generally radial direction relative to a second vertex, said third side being irregularly shaped, said third side having a length different from said first and second sides, the second vertex being spaced from the first vertex, a fourth side extending in a generally radial direction relative to the second vertex, said fourth side having substantially the same length as said third side, being substantially a rotational image of said third side and being rotationally spaced from said third side by a second angle of 360 degrees divided by m, where m is an integer greater than or equal to 2, a fifth side extending in a generally radial direction relative to a third vertex, said fifth side being irregularly shaped, the third vertex being spaced from the first and second vertices, a sixth side extending in a generally radial direction relative to the third vertex and being substantially a rotational image of said fifth side and rotationally spaced therefrom by a third angle, the sum of the first, second and third angles being substantially 360 degrees, each of said sides one through six having at least one spacer, and said spacers together defining a rotational tessellation comprised of x primary elements, wherein x is an integer equal to or greater than 1.