Origins of Marble
Metamorphic rock is a rock that has changed from heat and pressure. In this instance, marble, which is formed from limestone undergoes a process called recrystallization. The heat and pressure in the earth's crust causes changes in the composition of the limestone. Fossilized materials in the limestone, along with its original carbonate minerals, recrystallize and form large coarse grains and any impurities that are present in the limestone during this process affect the formation of the marble. The resulting minerals determine the variety of the marble.
Marble ranges in colour, is usually heavily veined and shows many grains. Pure white marble is the end product of the metamorphism of unalloyed limestone. Colours and veining in marble is determined by the presence of mineral impurities like silt, sand and iron oxides such as hematite and limonite which previously existed as particles or deposits in the limestone. Marble is classified into three categories, dolomite, magnesium and calcite, depending on the percentage of magnesium carbonate.
Marble is typically named after the colour of the stone (in Italian) and location of the quarry from which it is derived. For example "Bianco” means white in Italian and Carrara is a quarry in Italy, therefore Bianco Carrara marble is white marble that comes the city of Carrara.
Natural Marble
"Marble” is an expansive term, especially with regard to the construction industry. Any partly metamorphosed limestone that has a high density and is capable of taking a polish can be included in the definition. The construction characterization basically encompasses most massive crystalline rocks that are durable enough to be used commercially. This broad characterization is generally accepted because the performance and appearance of these rocks is more comparable to marble than to the actual scientific classifications of such.
Natural marble is extracted from a limited number of quarries worldwide and generally imported as slabs. There is an art to preserving the natural beauty of the stone and a certain degree of craftsmanship is required to maintain the esthetic while using marble as a building material, thus marble is a tremendous luxury as it is one of the most expensive materials to use commercially.
Cultured Marble
In addition to natural stone, there are man-made alternatives available for consideration such as cultured marble. Cultured marble is a precise mixture of fiberglass resin and crushed marble stone. Whereas the constitution of natural marble is dependent on the environment for production having variable shape and colour, cultured marble can be made to order.
First a specific mixture of polyester resin, catalyst, fillers and pigments are blended and poured into molds that have been coated with a clear gelcoat that has been specifically designed to generate a glossy, impermeable and durable surface that is very stain resistant and relatively easy to maintain. The shape and appearance of the end product are predetermined and entirely dependent on the manufacturing process.
The catalyst (a substance that increases the rate of a chemical reaction) causes the mixture to solidify and bond into a hard mass and after chemical curing occurs for a length of time, the cultured marble is then removed from the mold, refined, inspected and ready to be used for construction purposes.
Types of Marble Countertops
Marble is deemed to be one of the most beautiful building materials on earth and is a highly desirable addition to any home. The natural splendor of the stone has been used throughout time for both building materials in construction and as an art medium.
While the expense of marble is considered exorbitant for countertop material, the expense of marble slabs has become more accessible recently. The discerning customer also has the option of choosing cultured marble to achieve a comparable look without incurring as much cost.
Whether using natural or cultured marble for a countertop, the next step is to select the type of counter to be installed. The first variety is comprised of large slabs of marble that are put onto a specific style of cabinetry base that has the appropriate load bearing capabilities. This option is the more opulent choice because marble slabs are exceptionally strong and, with proper care, will last a lifetime. The second choice in countertop is marble tiling. The tiles are adhered to a countertop base with a special adhesive and then covered with a thick layer of protective sealant. These countertops are more cost effective because they use less marble.
The Benefits of Marble
As mentioned above, with proper care and maintenance, marble can last a lifetime. It is resistant to heat and to breakage. Marble is an invaluable tool for pastry chefs because its surface is cooler than room temperature and very smooth to allow for ideal pastry manipulation.
In addition its physical attributes marble's primary benefit is undoubtedly its appearance. Marble has an inherently random appearance that seems to glow. The variations of colour and pattern make each piece unique and provide a classical feel.
Marble is an indulgence that signifies sophistication and elegance. The stone seems to ebb and flow with the way it holds and radiates light and warmth. The luxury that marble creates in an interior is unrivaled. And because of the love and attention that marble countertops receive, they reflect the beauty of that care and age well. Even with aging and normal wear the marble develops character that can only be created when function and form combine to become the exquisiteness that is encompassed by marble.