The technical side of Granite
Granite is one of the oldest building materials known to man. The use of granite adds both permanence and style to any project. Granite will enhance your project with an aesthetically pleasing image while providing a façade of high performance with low maintenance.
By geological definition, there are hundreds of stone types commonly used as dimension stone products. The commercial
definitions of stones are much broader, allowing stones with similar mineralogy, workability, performance, and behavior to be combined into one classification, discounting the fact that they may be scientifically classified as different stone types. For example, stones such as gabbro, diabase, diorite, anorthosite, etc., are marketed commercially as granites because their properties are similar, even though they are not true granites by geological definition.
Most stones used in dimension stone applications will fall under one of five commercial definitions: Granite, Marble, Limestone, Quartz-Based, or Slate.
The term granite comes from the Latin root word granum, meaning "grain". The geological definition of granite is "any plutonic rock in which the mineral quartz makes up 10 to 50 per cent of the felsic components, and the ratio of alkali to total feldspar is between 65 and 95 per cent." Commercially, any holocrystalline quartz-bearing plutonic rock is generally included in the granite group
The granite group is one of the most versatile stone types available. Granite, and granite-like materials, are capable of taking a wide variety of finishes which allow the designer to custom-tailor the stone to the aesthetic or performance requirements of a specific application.
Resistance to scratching and durability in foot traffic areas are largely dependent upon the hardness of the minerals that make up the stone. In most granites, the primary minerals are quartz and feldspars, accounting for approximately 90% of the stone. The hardness of a mineral is oftentimes defined by use of Moh's Scale of Relative Hardness, developed in 1822 by the Austrian
This scale lists 10 minerals in ascending order of scratch resistance:
Feldspar and quartz are the minerals that give granite its exceptional abrasion resistance. This abrasion resistance contributes to its long service life in high traffic areas of public buildings.
Mineralogist Friedrich Moh.