Quartz is an engineered (man-made) stone. Quartz is a type of mineral, but when Quartz is mentioned for counterotps this refers to the enginnered prodcut made from quartz and resin.
Quartz is very durable and comes in a wide array of colors and patterns. Since Quartz is engineered it often has a uniform appearance. Quartz, like granite, is heat and stain resistant.
Pros: uniform coloring and patterns; durable/scratch resistant; stain resistant, no need to seal
Cons: lacks variation of natural stone; not all types are heat resistent; not recommended for outdoor applications or areas with heavy sun/UV exposure
MMG carries and works with many lines of Quartz including, but not limited to Caesarstone, Difiniti, Colorquartz, Cambria, Hanstone, Silestone, Viatera, and Zodiaq.