What is Marble, Limestone, Travertine, Slate & Granite?

Marble
Marble is a metamorphic rock resulting from the metamorphism of limestone, composed mostly of calcite (a crystalline form of calcium carbonate, CaCO3). It is extensively used for sculpture, as a building material, and in many other applications. The word 'marble' is colloquially used to refer to many other stones that are capable of taking a high polish.

Faux marble or faux marbling is a wall painting technique that imitates the color patterns of real marble (not to be confused with paper marbling). Marble dust can be combined with cement or synthetic resins to make reconstituted or cultured marble.

Places named after the stone include Marble Arch, London; the Sea of Marmara; India's Marble Rocks; and the towns of Marble, Minnesota; Marble, Colorado; and Marble Hill, Manhattan, New York. The Elgin Marbles are marble sculptures from the Parthenon that are on display in the British Museum. They were brought to Britain by the Earl of Elgin.

Limestone
Limestone rocks are sedimentary rocks that are made from the mineral calcite which came from the beds of evaporated seas and lakes and from sea animal shells. This rock is used in concrete and is an excellent building stone for humid regions.
Limestone is available as plain rock. Since it is not crystallized, it cannot be polished.

It is available in elegant shades of yellow, blue, brown and black. Due to its durability and longlife, limestone is generally used as building stone and for making statues. Its use as wall cladding material has also gained immense popularity.

Travertine
Travertine stone is a form of limestone. It often forms near hot bubbly mineral rich springs. Gas bubbles become trapped and create a pitted surface on the stone. These pitted surfaces can be filled with an epoxy or dust resin. Filling the small holes and pits gives the travertine a more finished look. A refined beauty. The stone surface can also be left in its natural state with the small holes and pits unfilled. This is a warmer aged look which will acquire a beautiful patina over time. Leaving the stone unfilled will affect the durability. It will stain and attract dirt much easier than a filled travertine.

Slate
Slate is metamorphic rock, like the marble. However, instead of forming from a pre-existing limestone (like marble), slate is formed from the low-grade metamorphism of the sedimentary rock shale and volcanic ash deposited on sea floors. Slate, like shale ("mudstone"), is a very fined-grained rock of mostly microscopic clay minerals with some microscopic quartz and calcite. Slate can also contain some of the same minerals found in granite, which make some slates iridescent and/or hard. The alteration of shale by heat and pressure produces the pronounced partings (slaty cleavage) that give slate its characteristics. Like limestone and marble, the color comes from trace metals. The wild colors on most Chinese and Indian slates are the result of splitting the slate along natural layers, which exposes the metals to the atmosphere, and they oxidize (rust).

Granite
Granite is an igneous rock, which, during its development, remains in the form of liquid magma in the center of the Earth. Unlike lava, granite did not come to the surface. It remained trapped inside the earth where it slowly cooled and crystallized. Due to the extreme pressure within the Earth, and the absence of atmosphere, granite is formed very dense with no pores. Granite is infact a host of ingredients, including common minerals like feldspar, quartz and mica, and the proportions vary considerably from deposit to deposit. The major mineral component of granite is feldspar. Quartz, which is the hardest part of Granite (it ranges from 70% to 80% the density of a diamond) comprises only between 10-30% of the rock, whereas feldspar (potassium and sodium varieties) makes up 60-80%. (This contrasts dramatically with GRANIREX, which is 93% natural Quartz).

Granite comes in various colors varying from stark white to beiges, browns, reds, pinks, yellows, greens, blues, grays and blacks. Textures range from clear to coarse and crystalline to heavily veined. These natural materials were created in the earth many years ago by processes and conditions, which gave each of them varying properties and characteristics.