Abstract: A block suitable for use in an arrangement of blocks that are interlocked. The block may comprise: a first side surface extending between a first edge and a second edge, the first side surface being irregular and having a first half and a second half that are congruent; a second side surface extending between the second edge and a third edge, the second side surface having a first half and a second half that are congruent; a third side surface extending between the first edge and a fourth edge, the third side surface being congruent with a first portion of the first side surface; a fourth side surface extending between the third edge and a fifth edge, the fourth side surface being congruent with a second portion of the first side surface such that the first portion and the second portion of the first side surface constitute the first side surface; and a fifth side surface extending between the fourth edge and the fifth edge, the fifth side surface having a first half and a second half that are congruent.

Abstract: An interlocking block for use in the construction of a mortarless retaining wall wherein a plurality of interlocking blocks are stacked in a number of successive offset courses of blocks, a block in an upper row being in overlapping relation with respect to the joint between blocks in an immediately underlying row. The interlocking block comprises an interlocking member and a block body having top and bottom support surfaces and rear, front and side surfaces.

Abstract: The present invention relates to a block interlock offsetting key for use in the construction of a mortarless retaining wall wherein a plurality of blocks are stacked in offset rows or courses, the blocks of the wall being provided with top and bottom grooves. The block interlock offsetting key is able to interlockingly engage the bottom groove of a block and the top groove of an underlying block so as to offset the blocks a predetermined distance with respect to each other.