Natural stones are stones produced by the Earth. Quarried stone is processed by polishing, brushing and hammering to improve its features, such as shine and smoothness. Natural stone flooring is the sustainable choice for everyone. It will last as many lifetimes as you wish to name. Natural stones are classified according to their mineral content and the process of their formation. Good stones are characterized by durability, hardness, strength, amenability to dressing, appearance, weight, fineness of grain, compactness, porosity and absorption. In order to be suitable as building stones, a rock should have specific qualities such as capacity to stand the ravages of time and weather, requisite strength to bear strain and super-incumbent weight, attractive colour and general appearance. Its structure must also be such as to allow quarrying into good sized blocks or planes.
Natural stones can be classified into two general categories according to its composition -
Calcareous stone - It is composed mainly of calcium carbonate. It is sensitive to acidic cleaning products and frequently requires different cleaning procedures than siliceous stone. Types of calcareous stone include marble, travertine, limestone and onyx.
Siliceous stone - It is composed mainly of silica or quartz-like particles. It tends to be very durable and relatively easy to clean with mild acidic cleaning solutions. Types of siliceous stone include granite, slate, and quartzite. Knowing the difference is critical when selecting cleaning products. What may work on siliceous stone may not be suitable on calcareous surfaces & vice versa.
Absorption Rating -There are 4 levels of absorption that a tile can have,
Non-vitreous - This is the highest absorption level. In most cases non-vitreous tiles should not be used in any damp environment.
Semi-vitreous - While these tiles are less absorbent, the more liquid they are exposed to, the more maintenance they will require.
Vitreous - This is the standard absorption level for flooring tiles and these materials are generally considered appropriate for most low to mid traffic indoor and outdoor applications.
Impervious - These materials are resistant to the absorption of liquids and thus will be easier to maintain. They are often used in high traffic commercial applications.
Specific Tile Absorption Rates - In general, Sandstone is the most porous natural stone material, Travertine, Limestone, and Slate have medium absorbency, and Granite is relatively waterproof. Polished materials also absorb less water than honed or cleft surfaces.
Grade - Some retailers use a grading system to rate the quality of materials. This can refer to the size, shape, and thickness of the tile, as well as the condition of its surface. Most grading systems have three levels of quality. Grade 1 refers to high quality, uniform materials. Grade 2 consists of materials with minor defects such as chips, scratches, or irregular surfaces. Grade 3 materials have major flaws in size, shape, surface, or chipping, making them appropriate only as accent pieces, or in certain rustic decorative applications.
Each piece of stone is a unique creation of the earth, making every flooring application one of a kind.
The mountain born qualities of the stone can help to reconnect a space with the natural world.
While there is some debate about the ecological impact of quarrying and transporting stone materials, the tiles themselves are natural, nonpolluting, eco-friendly pieces. Purchasing stones which were acquired locally can cut down on the environmental impact of transport.
With the exception of Granite and some Slate, natural stone is quite porous, and needs to be treated with a sealing agent periodically to protect its surfaces.
Some polished materials such as marble can scratch easily.
Some stones are also very brittle, and will chip easily.