Quartz Kitchen Worktop – Thermal Shock Crack Quartz kitchen worktop (engineered stone) suffered a large crack, loosing a very large piece, due to thermal shock; rapid exposure to high heat. 1 Harsh crack, right through the kitchen worktop 2 Entire kitchen worktop corner is separated 3 Another angle 4 The surface is separated and cleaned 5 The stone is clamped with coloured glue 6 After careful bonding it is flush 7 Damage is barely visible 8 Worktop is back in action! see more repairs