Quartzite is harder than granite, it's quite durable. It withstands heat very well. Quartz is hard too (see our quartz slab), but not quite as hard as quartzite. The resin used in manufacturing quartz countertops (see Caesarstone Quartz for countertops) is a plastic, so it is prone to melting in heat above 300 degrees Fahrenheit. Watch below as we demonstrate the heat resistance that quartzite holds over quartz.