Types of Stones

Dolomite

A Marble-type stone that contains high amounts of magnesium and is harder and more brittle than pure marble.

Granite

A very hard, crystalline, platonic rock (formed far below the surface of the earth by slowly cooling magmatic bodies) of various colors consisting of feldspar, quartz (crystalline -2-silica) and smaller amounts of other minerals. Granite is very hard and more resistant to damage than marble, making granite more difficult to harm and correspondingly more difficult to restore than marble. Care of granite is similar to marble except more work is required, however the work is required less often. As a practical matter, a final high gloss finish on granite is generally achieved by using power driven Polishing tools and fine Grit diamonds.

Limestone

A highly porous rock consisting of calcite mainly from marine sedimentary origin that has not been re-crystallized by metamorphic conditions or precipitated from mineral springs. Some very compact limestone’s may be polished to a high luster.

Marble

A commercially applied term to any marble, limestone, or dolomite that can take a polish. The term marble is also commonly used by those unfamiliar with different stones to refer to any polished natural stone. Pure marble contains 99% calcium carbonate (CaCO3) and is formed by re-crystallization of sedimentary limestone when subjected to metamorphic conditions. Metamorphic conditions occur in the presence of heat and pressure below the earth’s surface. The limestone melts and crystallizes into marble, a highly compacted crystalline structure with uniformity of grain and hardness which can be polished to a high luster. During this process, minor impurities such as chlorides, sulfur, silicates, iron and organic residues mix into the limestone producing varying colors and veining in the stone.

Onyx

An agate-like stone often translucent with a layered appearance. It is formed in cold mineral springs by calcite precipitatio.

Quartzite

A metamorphic Sandstone where the grains of quartz in sandstone become fused giving rise to a hard crystalline rock.

Sandstone

A sedimentary rock composed of rounded grains of quartz bound together by silica or lime.

Serpentine

A rock composed primarily of hydrated magnesium silicate that is green, yellow, or brown in color; it gets its name due to the resemblance to a serpent’s skin. Many so-called green marbles are actually serpentines, not marbles.

Siliceous Stone

All natural stone that is primarily composed of silicates or silica. These stones are resistant to acid attack and are usually more difficult to polish to a high luster compared to calcite stones you will find this mineral in granite and quartizites

Slate

A compact fine grain metamorphic rock that possesses slaty cleavage and hence can be split into slabs and thin plates. It is composed primarily of silica and alumina.

Soapstone is the common name for the mineral steatite. Steatite is at least 50% talc combined with other minerals, mostly magnesite, that have been geologically metamorphosed into stone through a combination of heat, pressure and time. It is called soapstone because the talc gives the stone a soapy feel.

Terrazzo

A man-made stone composed of chips which are mixed with cement and then polished as an economical alternative to solid marble slabs or tiles. Care of terrazzo is identical to the care of marble.

Travertine

An ivory to golden brown or reddish colored calcite stone formed over hundreds of thousands of years by precipitation of calcite in hot mineral springs. It comes out of the ground relatively soft, but hardens with age and exposure. It has a sponge-like texture with up to 1/2 inch cavities. These cavities are generally filled with a matching Portland cement when used in construction.