These are high grade Texas river cobbles that have been spalled into workable pieces. Your purchase will contain 10lbs of premium (Grade-A) spalls that range from 4-7 inches long. Stone shown in the picture is an example of what to expect. This material is not heat treated, Actual pieces may vary, a 10lb box contains Approx. 7-8 spalls depending on size and weight of each piece. Skill Range: Intermediate to Expert.