LIMESTONE
The principal mineral that composes limestone is Calcite, a testament
to the sea-based life forms found many times in its structure.
Limestone formation happens when, given millions of years, layer
upon layer, solidification occurs from the immense weight of laden
sediment. This sediment contains many minerals which become the coloring
agents of the stone. Their color is typically some shade of beige,
but may be white, yellow, pink, purple, reddish brown or black. Limestone
varies in form due to easy solubility and types of deposits that
are found in sea beds’ caves and mountains. Different limestones
have different levels of hardness. Certain limestones are hard enough
to maintain a polish but many more can only be honed. The texture
of limestone is typically fine and often the shells that caused its
formation are clearly visible. It is the softest of the quarried
stones used today, but many times limits the application to only
residential.
TRAVERTINE
Travertine is also a sedimentary stone that was formed
similar to Limestone. One of the primary differences between the
two
is that during the formation of Travertine, hot water percolated
through
the stone thus causing holes and voids that are not always seen
in Limestone. Travertine is available filled or unfilled. The “filled” product
has the holes filled at the factory and honed. The unfilled product
can be left open or filled in the field by the installer. This
product also comes in numerous colors due to different minerals
that occurred in the formation process. Trinity currently provides
travertine tiles and slabs from several countries including Italy,
Turkey and Mexico. The colors range from light crème to
dark walnuts and bright golds. The tiles are available in numerous
finishes including honed, brushed, tumbled, saw cut and sandblasted.
GRANITE
Granite is an igneous rock that was formed from the hardening of
expelled magma following volcanic eruptions. The material cooled
inside the earth’s crust and thus created the crystalline
structure that we have come to be familiar with. If a piece of
granite is crushed to powder, one could easily pick out the tiny
fragments of separate substances that comprise it. These tiny
fragments are mainly feldspar and quartz. Feldspar is the mineral
used by nature as a soldering element – to enable the
various minerals to adhere to one another. Feldspar is integral
to the
integrity of granite by fusing the various minerals into crystals.
Granite is low in calcium, metallic iron and magnesium… as
a result, is it extremely hard and difficult to scratch or chip.
Its mineral formation gives granite a higher resistance to the
acids commonly found in everything from orange juice to common
rain.
The preva
iling color of granite is gray; however, greens, reds
and many other colors are determined by the different kinds of
feldspar and minerals present. Granites can come in numerous
finishes including polished, honed, flamed, sandblasted and brushed.
MARBLE
Marble is a metamorphic limestone. It is composed of calcite which
makes it fairly soft, however easy to work with. It is formed
just like limestone. The same layers of calcium carbonate and
minerals that are found in the formation of limestone are also
found in marble. Except these minerals have undergone additional
heat and pressure causing re-crystallization, forming a much
more dense and harder composition that its limestone origins.
Pure marble is almost entirely white. It varies in color, from
black to white, through almost every shade of the spectrum. Impurities
such as silica, iron oxide and graphite give its characteristics
rich veining, clouding and color. This is what makes the product
have such range in denseness and hardness. Marbles are available
primarily in polished, honed and brushed finishes.
SLATE
Slate is a metamorphic rock. It is formed when sedimentary shale
is under pressure and heated by magma. It is composed principally
of Muscovite and the decomposition of feldspars and quartz.
Therefore it is normally softer than a marble or granite. Slate’s
offer a wide variety of colors and textures to choose from.
Some are more durable for commercial applications than others.
Also,
due to the iron that present in certain slates, you must be
careful when choosing slate in wet areas and exterior applications.
The
iron can rust and leach out of the stone and cause staining
and damage to surrounding areas. Slate primarily comes in cleft
finish
but several can be special ordered in honed and polished.
