Heat Is the One Real Limitation
Two Materials in One Slab
Roughly nine parts crushed mineral to one part polymer resin, by weight. The mineral fraction is what gives quartz its hardness and its resistance to scratching. The resin fraction is what makes it non porous and holds the whole thing together, and it is the part with a temperature limit well below what a pan base reaches.
What Damage Looks Like
Two forms. A scorch mark, which is a discoloured patch where the binder has degraded, and thermal shock cracking, where a sudden temperature difference across a small area sets up stress the slab cannot absorb. The second is more likely near a cutout, because a cutout corner is already the weakest geometry on the top.
Why It Cannot Be Polished Out
A scratch is missing surface and can be removed by taking the surrounding surface down to meet it. A scorch is chemically altered binder that goes down into the material. Polishing exposes more of the same damaged resin. This is the practical difference between quartz and natural stone when something goes wrong.
The Realistic Risk Points
Directly beside a hob, beside an oven where a hot tray is set down, and around a boiling water tap where repeated local heating happens in one spot. Slow cookers and countertop appliances left running in the same position for hours are a slower version of the same exposure and are easy to overlook.
Trivets, Not Vigilance
The failure mode here is a single lapse, so a rule that depends on remembering will eventually fail. A permanent trivet or a stainless landing strip beside the hob makes the safe action the convenient one. That is a five minute purchase against a defect that cannot be repaired.
What the Warranty Says
Every manufacturer excludes thermal damage explicitly, and they inspect for it, because a scorch has a recognisable signature. There is no argument available on this one. It is the clearest case in the whole category where prevention is the only available strategy.