What is Marble? Marble is a metamorphic rock formed by alteration of limestone or dolomite, often irregularly colored by impurities and used especially in architecture and sculpture. Marble slabs and tiles are suitable for bathrooms, entryways and fireplaces, living & dining areas. Marble floor tiles and slabs are also used for both interior and exterior flooring applications. Indian marble stones are easily available in the form of blocks, slabs and tiles. Some of the different colors of Indian marble are white marble, Indian green marble, Indian pink marble, black, blue, mottled and banded, grey. Marble, formed from limestone with heat and pressure over years in the earth's crust. These pressure or forces cause the limestone to change in texture and makeup. The process is called recrystallization. Fossilized materials in the limestone, along with its original carbonate minerals, recrystallize and form large, coarse grains of calcite. Impurities present in the limestone during the recrystallization period affect the mineral composition of the marble which is formed. At relatively low temperatures, silica impurities in the carbonate minerals form masses of chert or crystals of quartz. At higher temperatures, the silica reacts with the carbonates to produce diopside and forsterite.  At a very high temperatures, rarer calcium minerals, such as larnite, monticellite, and rankinite, forms in the marble. If water is present, serpentine, talc, and certain other hydrous minerals may be produced. The presence of iron, alumina, and silica may result in the formation of hematite and magnetite. The minerals that result from impurities give marble a wide variety of colors. The purest calcite marble is white in colour. Marble containing hematite are reddish in color. Marble that has limonite is yellow, and marble with serpentine is green in colour.

Physical Properties of Marble

Origins

Marble is a metamorphic rock resulting from regional or at times contact metamorphism of sedimentary carbonate rocks, either limestone or dolostone. This metamorphic process causes a complete recrystallization of the original rock into an interlocking mosaic of calcite, aragonite and/or dolomite crystals. The temperatures and pressures necessary to form marble usually destroy any fossils and sedimentary textures present in the original rock.

Pure white marble is the result of metamorphism of very pure limestone. The characteristic swirls and veins of many colored marble varieties are usually due to various mineral impurities such as clay, silt, sand, iron oxides, or chert which were originally present as grains or layers in the limestone. Green coloration is often due to serpentine resulting from originally high magnesium limestone or dolostone with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure and heat of the metamorphism.

Types of Marble

Some historically important kinds of marble, named after the locations of their quarries, include:

Thassos from Greece
Paros from Greece
Penteli from Greece
Carrara and Luni from Italy
Proconnesus from Turkey
Connemara from Ireland
Black Marble from Kilkenny, Ireland
Macael from Spain
Makrana from India
Danby from Vermont
Yule from Colorado
Royal White from China
Beijing White from China
Vietnam White from Vietnam
White marbles, like Carrara in Italy,Royal White and Bejing White in China, have been prized for sculpture since classical times. This preference has to do with the softness and relative isotropy and homogeneity, and a relative resistance to shattering. Also, the low index of refraction of calcite allows light to penetrate several millimeters into the stone before being scattered out, resulting in the characteristic "waxy" look which gives "life" to marble sculptures of the human body.
Chemical Composition of Marble Indian marble has the following main chemical constituents in its composition.
Soluble residue - 0.89%, Fe2o3 - 0.28%, CaCo3 - 97.74%, MgCo3 - 1.22%, Phosphoric Acid - 0.04%