Made from one of the hardest minerals on earth, quartz countertops are arguably the most durable option for kitchens. They're also some of the most eye-catching. They come in a wide variety of colors, including fire-engine red and apple green, as well as earthy browns, blacks, and creams, with sparkles and veining for the look of granite or marble. But unlike natural-stone slabs, which are mined, these slabs are engineered in a factory. Their primary ingredient is ground quartz (about 94 percent), combined with polyester resins to bind it and pigments to give it color. For some designs, small amounts of recycled glass or metallic flecks are added to the mix. The resins also help make these counters stain and scratch resistant—and nonporous, so they never need to be sealed. Compare that with granite, the reigning king of high-end countertops, which typically requires a new protective top coat at least once a year.