Interlocking erosion control block with integral mold

A construction block, comprising;

• a heavy material;
• a mold constructed of a moldable material, said mold including a circumferential edge band formed of the moldable material throughout the thickness of said edge band, said edge band having an inside surface defining a circumferential side edge of said heavy material, and said edge band having an outer surface defining the shape of said block;
• said mold including one or more opening members attached to said edge band for defining respective openings in said block extending from a top surface of said block to a bottom surface of said block, each said opening member disposed inside said circumferential edge band, and no portion of said mold extends from said circumferential edge band to the opening members which is visible when said mold is filled with said heavy material;
• a respective web of moldable material connecting each said opening member to the inside surface of said circumferential edge band, said webs located so as to be fully embedded in said heavy material;
• said heavy material filling said mold, inside said circumferential band except for an inner part of each opening member;
• and
• said mold formed so that when said heavy material fills said mold, said mold does not cover the openings at either opposing end thereof.