Natural stone products are powerful enhancements to any building project, and the results achieved are of a high end associated with the warmth of a natural product.

In this page, we briefly comment (in geological and commercial terms) the classifications and conceptual definitions of the stones that are commonly used for ornamental and for construction purposes.

Geologically speaking . . .

Rock Classifications

1.       Igneous - a rock formed by a crystallization of magma or lava.

1.1.    Igneous Extrusive – fine-grained igneous rock formed by the crystallization of lava on the earth’s surface.

1.1.1. Basalt – originated by most recent volcanoes that produced flows of blacker lava that was spread on the surface and hardened into a black and gray stone. Presently, the commercial value of this stone is growing rapidly.

1.2.    Igneous Intrusive – magma does not always reach the surface to build a volcano or pour out in a lava flow, so it remained below the surface and cooled.

1.3.    Plutonic Rocks – rocks formed with high pressure and high temperature but kept inside the earth’s crust. Coarse-grained and composed of primarily identifiable primary minerals (quartz, feldspar, mica, dark minerals).

1.3.1. Granite - is an igneous plutonic rock, which during its development was melted volcanic lava, but unlike the lava, never reached the surface. Without reaching the outside, this molten rock very slowly cooled and crystallized forming a very uniform speckled stone. Essential recognition characteristics for granites are the randomness of the mineral grains and the compact structure, once there are almost no recognizable cavities. In granite, quartz never occurs with its typical crystal form since it is the last mineral to be precipitated from the melt as it solidifies and can therefore only fill in those spaces left in the rock. 

2.       Sedimentary Rock – formed by sedimentary processes, mainly a single, low temperature mineral. It is banded, stratified and often presents presence of fossils.

2.1.    Dolomite – a rare rock, formed by the precipitation of the seawater and lagoons and lakes in continental areas.

2.2.    Limestone - a rock composed primarily of calcite or dolomite. The varieties of limestone used as dimension stone are usually well consolidated and exhibit a minimum of graining or bedding direction.

2.3.    Sandstone – a very common rock, formed primarily by sand deposited where once was a beach. As once was wet, it is thoroughly stratified and easily quarried.

2.4.    Travertine – formed by the evaporation of spring water, rich in calcium and carbonate, both in rivers near waterfalls and in caves by deposits of thermal water in subterranean cavities.

3.       Metamorphic Rock - altered in appearance, density and crystalline structure, and in some cases mineral composition by high temperature or intense pressure or both. Slate is derived from shale; quartz-based stone from quartzitic sand; and true marble from limestone.

3.1.    Slate - a very fine-grained metamorphic rock derived from sedimentary rock shale. Characterized by an excellent parallel cleavage entirely independent of original bedding by which cleavage the slate may be split easily into relatively thin slabs.

3.2.    Marble - a crystalline rock composed predominately of crystalline grains of calcite, dolomite or serpentine, and capable of taking a polish, marble is a metamorphic rock that once was a limestone, but over time the combination of intense heat and pressure caused the limestone to crystallize again. Different substances entered the composition of the stone during this process, creating the infinite variation of colors and veining.

Commercially speaking . . .

The name granite derives from the Latin ("granum"=grain) and refers to the granular texture.

The general impression of granite is always of a light colored rock, regardless of whether it looks gray, yellowish, brownish, bluish or reddish. 

Granite is a widely used stone for building and decorative work. It wears extremely well and is highly resistant to weathering. Functional and durable, is ideal for kitchen counter tops, bar tops, accents islands and dining tables. Granite is the most durable architectural building stone.

The increasing popularity of this stone is a result of its beauty and versatility. Used in a wide range of commercial and residential applications, granite is ideal for tile floors, walls and countertops, as well as exterior applications such as pavers and wall cladding.

Granite is quarried worldwide. More quarries are discovered every year increasing the color choices and keeping the prices competitive.

The term marble (Greek "shimmering block of stone") is defined in different ways. In scientific petrology it is defined as a calcitic metamorphic rock, the true, crystalline marble. In the building industry, any solid limestone, which will take a polish, is called marble.

Marble has a peculiar characteristic that no two pieces are alike, and marble differs from limestone by a few characteristics:

Marble is a very elegant and luxurious stone. Its beauty, originality and versatility will allow it to be used in many applications such as floor tiles, wall tiles, fireplaces, columns, water tables, steps, thresholds and windowsills, etc. Throughout the house, in the bath, it will shine its best; can be used in every surface, including vanities, shower walls, tub decks and flooring or wherever imagination can allow you.

In the building industry, any solid limestone, which will take a polish, is called marble. Limestone is a sandy sedimentary rock formed closer to the earth’s surface and often captures fossilized plant and animal life. Similar to marble and granite, limestone is processed for a wide range of interior and exterior building applications, including floor tiles, wall tiles, fireplaces, columns, water tables, steps, thresholds and windowsills, etc. Limestone can be polished to a gloss finish, but it is more commonly known for its honed (mate), tumbled (antique or acid washed), and natural (rough) finishes. Colors are typically more neutral tones. 

Is a variety of limestone, which is precipitant from hot springs. Some varieties of travertine take a polish and are known commercially as marble. It is the classic construction stone for facing and paving. Travertine mostly know for its porosity, is comprised primarily of calcium carbonate. Slabs and tiles are cut from blocks with the veining (regular cut) or across the veining (cross-cut). Processors of this material will market the stones as is, with the holes for a more rustic and antique look, or fill the holes with a tinted epoxy and hone or polish the surface to achieve a solid surface effect. The stone is used in a wide range of interior and exterior building applications, including floor tiles, wall tiles, fireplaces, columns, water tables, steps, thresholds and windowsills, etc.

Slate is a fine-grained metamorphic rock that splits into thin and smooth surfaced layers. It is an economical choice and this stone is also used in a wide range of interior and exterior applications. The most common building application for slate is floor, wall and roof tiles and fireplace surrounds.

It is a metamorphic rock basically composed by mineral talc. This natural quarried stone is softer than most other natural stones. Although a soft stone, soapstone is a very dense (non porous) stone.

It is wrong to associate softness with porosity; soapstone is denser than marble, slate, limestone and even granite. Because soapstone is so dense, it will not stain if anything is spilled on the stone surface, it will not penetrate the stone. Other natural stones, including granite, if not properly sealed may stain.

Very easy to maintain, can be cleaned with any common household cleaners. The only maintenance required for soapstone, is the application of mineral oil.

Largely used for road paving and crushed stone for road and railroad ballast, and it is consolidating a growing importance as a building and decorative stone. Applications are primarily tiles, curbsides and cladding. 

A semi-precious stone, Onyx is a mineral in formation and not a rock. It is a carbonate (Calcite) formed by quartz crystals, fused together by nature into translucent layers of stone, revealing a rainbow of colors ranging from creamy whites, gold and ambers to orange, reds, browns deep greens, and grays. A natural process of heat and pressure creates a crystalline stone rich in color and pattern that reaches well below the surface to reveal an inner warmth and opalescence.

Its beauty and translucency allows it to be used in a variety of applications ranging from installations in floors, walls, fireplace mantels, counters, bathtubs, pedestal sinks, dining tables, cocktail tables, extension tables, consoles and chairs and versatile way. 

 

To fully appreciate the beauty and particularity of any ornamental stone, you must see and feel it for yourself. Call us and set up an appointment. We will be happy to assist you in this experience.