Abstract: A block mold for forming a block, comprising a bottom wall, a side wall movable relative to the bottom wall, and a textured material on the side wall (e.g., near a bottom portion of the side wall) and adapted to create a textured surface on the block when the side wall is moved relative to the bottom wall. The textured material comprises abrasive particles (e.g., ten to sixty micron diamond grain) in a matrix (e.g., nickel alloy). In one embodiment, opposing first and second side surfaces of the side wall form two adjacent mold cavities, and the first and second side surfaces each include textured material (e.g., on a lower portion of the respective side surface). Preferably, the side wall includes a side surface defining a plane, and the textured material is applied to the side surface to create the textured surface that protrudes from the plane.