Compac is simply a brand name, but you’re asking an excellent question regarding the difference between Quartz and Quartzite.
o Quartz is a man-made (engineered) countertop material. It is made of crushed stone, some color, and anywhere between 5% - 12% resin, epoxy, and glue to bind these materials. This creates the hard material that it is.
o Quartzite is a natural stone that used to be a form of sandstone with high natural quartz content. With heat and compression underground, everything crystalizes and bonds together. Some quartzites are opaque while others have a translucence ideal for backlighting. Many quartzites can be actually harder than many granites as well.