The form liner of the present invention simulates a natural stone wall having a random pattern. The form liner comprises an outer edge and a surface that is contoured to resemble a plurality of stones held together by an adhesive substance. The outer edge of the form liner has six connection regions made up of multiple linear segments. No two adjacent connection regions are connected at a ninety degree angle and no linear segment of the fifth connection region lies along the same linear path as any linear segment of the sixth connection region.