Granite is an igneous rock. This means that at one time during its development, it was melted like volcanic lava. Unlike lava, however, this melted rock never reached the surface. It remained trapped inside, where it slowly cooled and crystallized, resulting in a very uniform, speckled stone that ranges in color from blacks and grays to pinks, browns, and reds. Polished granite is a very durable stone, much harder than marble.
Granite has been popularly used for commercial purposes for many years. Granite can often be found on building exteriors, interior walls, and “high-traffic” floors. Granite will withstand almost any element including heat and cold.
Quartz is an engineered stone: a composite material made of crushed stone bound together by an adhesive, (most commonly polymer resin, with some newer versions using cement mix). This category includes engineered quartz, polymer concrete and engineered marble stone. The application of these products depends on the original stone used. For engineered marbles, the most common application is indoor flooring and walls, while the quartz-based product is used primarily for kitchen countertops as an alternative to laminate or granite. Unlike terrazzo, the material is factory made in either blocks or slabs, cut and polished by fabricators, and assembled at the work site. The quartz version (which end consumers are much more likely to directly deal with) is commonly known as 'quartz surface' or just 'quartz.'