Granite
The word granite comes from the Latin granum, a grain, in reference to the
coarse-grained structure of such a crystalline rock. Granite is a common and
widely occurring type of intrusive, felsic, igneous rock. Granites usually
have a medium to coarse grained texture. Occasionally some individual
crystals are larger than the groundmass in which case the texture is known
as porphyritic. Granites can be pink to dark gray or even black, depending
on their chemistry and mineralogy. Granites sometimes occur in circular
depressions surrounded by a range of hills. Granite is nearly always
massive, hard and tough, and therefore it has gained widespread use as a
construction stone. The average density of granite is 2.75 g/cm3. Granite
has been extensively used as a dimension stone and as flooring tiles in
public and commercial buildings and monuments.
Marble
Marble is one of seven natural stones which have a massive demand in the
world market. To the geologist, marble is a non-foliated, granular
metamorphic rock that is formed by the metamorphism of limestone and
dolostone. A number of minerals and gems can form in marble. Spinel from
Vietnam, ruby and sapphire from Myanmar (formerly Burma) and lazulite from
Afghanistan are just a few examples. Construction marble is a stone which is
composed of calcite, dolomite or serpentine which is capable of taking a
polish. With it's varied range of colours, textures and veining,
marble is the ideal decorative material for fireplace hearths and back
panels, vanity tops, walls and floors. Marble can be cut and polished in
many different ways; with the latest CNC machine technology almost anything
is possible, from a simple polished ogee edge to a 3 dimensional motif
carved in the face.
Travertine
Travertine is a form of limestone deposited by mineral springs, especially
hot springs. Travertine often has a fibrous or concentric appearance and
exists in white, tan and cream-colored varieties. It is formed by a process
of rapid precipitation of calcium carbonate, often at the mouth of a hot
spring or in a limestone cave. It is frequently used in Italy and elsewhere
as a building material. Travertine is a terrestrial sedimentary rock, formed
by the precipitation of carbonate minerals from solution in ground and
surface waters, and/or geothermally heated hot-springs.
Onyx
The name Onyx comes from the Greek word onyx means nail of a finger or claw.
Legend says that one day while Venus was sleeping Eros/Cupid cut her
fingernails and left the clippings scattered on the ground. Because no part
of a heavenly body can die, the gods turned them into stone which later
became known as onyx. Onyx is also mentioned in the Bible at various points,
such as the priests' garments and the foundation of the city of Heaven in
Revelation. Use of Sardonyx appears in the art of Minoan Crete, notably from
the archaeological recoveries at Knossos. Onyx was used in Egypt as early as
the Second Dynasty to make bowls and other pottery items.
There is a wide range of prices for marbles, limestone and granites with a lot of overlap. Cost of stone is determined not by type of stone or the look. Cost is mostly determined but by availability of material from quarries, accessibility and shipping costs. As a guide, mid-ranged priced granite and marble are similar in price.