What is so-called "Granite"?

Granite

A common, coarse-grained, light-colored, hard igneous rock consisting chiefly of quartz, orthoclase or microcline, and mica, used in monuments and for building. Granite - Derived from the Italian word, "Granite" meaning "grained." It is a very hard, crystalline, igneous or metamorphic rock primarily composed of dark minerals. Mineral grains are visible to the naked eye. This material is frequently characterized as more resistant to damage (e.g.staining, etching, etc.), harder, and more uniform than marble, travertine, onyx,limestone or slate.

A crystalline igneous rock that consists largely of alkali feldspar (typically perthitic microcline or orthoclase), quartz, and plagioclase (commonly calcic albite or oligoclase). Its average grain size is 0.04–1.0 in. (1–25 mm); finer-grained rocks of this composition include rhyolite and aplite, and coarser-grained ones are granite pegmatite.

Granite rocks are igneous rocks which were formed by slowly cooling pockets of magma that were trapped beneath the earth's surface. Granite is used for long lasting monuments and for trim and decoration on buildings.

Material Notes: 
Granite is an igneous rock with a mixed texture and grain size > 3 mm (plutonic). It is acidic, with a total silica content greater than 65%. The critical mineral of granite is quartz (5-35%); and also contains orthoclase feldspar, plagioclase feldspar, and smaller amounts of biotite.

Granite is used in architecture and construction because it is common and can possess a variety of textures and colors.

Granite is a primordial stone with naturally occurring variations in color and pattern. These variations, referred to as 'movement', should be expected and are the source of its natural beauty.  Also, keep in mind that the veining in the granite can effect color perception. Sometimes two different grain sizes occurring in the same slab will appear to be of a different color. Mineral concentrations may cause patches that appear darker or lighter.

Every slab of granite varies somewhat  within any given color and pattern. If you are unfamiliar with granite, a granite slab ordered may not be identical to a sample you are shown. While the samples are intended to represent the quarry's product, each slab may differ slightly in color and veining. Indeed, even a single granite slab will have color variations from one end to the other. This lack of predictability gives the product its unique character and adds an element of nature into human-designed spaces.