What is Quartzite?

Quartzite is a compact, hard and granular stone formed of sandstone which has been metamorphosed and structurally altered through recrystallization. A quartzite stone is composed primarily of silica or quartz. But there are some other minerals as well though small in quantity, like feldspar, mica, rutile, tourmaline, and zircon. The stone is quite smooth and mainly found on ridges and hilltops among ancient stones. Quartzite is very resistant to chemical agents and soil. Though pure quartzite is white to grey. Distinguishing a quartzite from a sandstone is not difficult as a quartzite has fractures across its constituent grains of sand, while sandstone fractures along the line of the cementing material between the grains of sand.

Formation:
In the organic regions, the quartz sand grains and quartz silica of sandstones are often recrystallized due to heating and pressure related to tectonic compression of the are. This metamorphic sandstones later become quartzites. There are two metamorphism processes for sandstones to turn into quatzites. Under the first process, the sand grains recrystallize under high pressure and temperature and form an interlocking mosaic of quartz crystals. Consequently, the original sediments change completely. This process is known as metaquartzite.
On the other hand, when the sand grains recrystallize under low pressure and temperature, some circulating fluids spaces between sand grains with silica cement. This type is called the orthoquartzite. Orthoquartzite is composed of usually well rounded quartz grains cemented by silica.

Features:
* Quartzite is normally white, light grey, yellowish, or light brown, but is sometimes they can be found in blue, red, green, purple, or black due to some other minerals present in them.

* A quartzite is quite hard and if broken it breaks across grains.

Basic Facts about Quartzite:

GROUP TYPE Metamorphic
COMMON MINERAL GROUP Siliceous
COMPOSITION Primarily quartz, but small amount of other minerals
are found which give color variations
POROSITY 0.4-3.9%
ABSORPTION 0.1-1.4%
WEATHERING EFFECTS Highly resistant
TENDENCIES Absorbs small amount of soil
Color: White, grey, reddish
FINISHING Textured/honed/satin finish

Please remember that although quartzite is highly resistant to liquid/fluid agents, use of oil repellent is highly recommended if you are using them in the kitchen.