Granite at the quarry.
Granite Composite is one of the most durable sink materials on the market today. Granite on its own has a high-density hardness. Coupling that with the filler polymers used to bind the composite materials together, makes for an extremely hard-wearing, stain, scratch and chip-resistant surface that can withstand heat up to 260 degrees Celsius. Composites are low maintenance and come in both undermount and countertop styles in a bevy of colours and layouts.
No Cutting, Dropping Heavy Objects
While extremely hard wearing, granite composite sinks are not indestructible. If they are cut with knives, this can scratch and mar the surface so that it can only be restored by refinishing. Also, unlike a stainless steel sink where you can drop a pan or heavy item without fear of damage, the Granite Composite sinks contain natural stone that can crack, plus this is a surface on which things don't bounce.
Be mindful when setting heavy items into the sink. And if the kids are in the habit of dropping their cups, plates and cutlery into the sink at a distance, as some are wont to do, retrain them to gently place items into the sink. Don't place any hot pan or dish into the sink that is hotter than 500° F or 280° C to prevent heat damage, scarring or possible cracking.
Regular Maintenance Cleaning
Rinse down after each use with clear warm or tepid water and a nonabrasive scrubber pad or nonabrasive cleaner, such as liquid Soft Scrub sans bleach or powdered Bar Keepers Friend. Even household baking soda will accomplish the same effect without the chemical additives. Always rinse well with warm or hot water so gritty residue is not left in the sink.
Removing Stains or Buildup
A soft scour pad such a those made by Scotch-Brite can be used to lift any caked debris or stains. For white calcium deposits or really stubborn stains, use Lime Away or CLR, letting it sit for 20-minutes or so, then scrub and rinse away. If deep-set stains occur, like a glass of grape juice was spilt and allowed to sit unrinsed in your pale grey granite sink overnight, soak the sink overnight with a diluted bleach solution covering all of the stained areas. Mix 1 part household bleach to 10 parts water. Drain the sink in the morning and give a light scrub over stains if needed and rinse well.
Rinse well. Use of strong chemicals, abrasive powders and steel wool pads will degrade the surface and make the sink more susceptible to stains.