Abstract: A variable mosaic pattern formed from interfitting blocks formed into standard shape is disclosed groups with curved or serpentine shapes. Interchangeability of the groups of the standard shapes permits easy installation, and production machinery presently available permits low cost manufacturing of the interchangeable components, which can be made of a suitable plastic molded from suitably shaped molds or stamped out on presses, cut from slabs of stone, or formed by other suitable means. The interchangeable components can be assembled indefinitely in any direction in an ever-changing mosaic pattern creating a random decorative effect.