Kinds of stone


Igneous Rock


This rock is formed when magma cools underground and crystallizes, or when it erupts onto the surface of the earth, cools and crystallizes. Magma that erupts onto the surface is called lava. When magma cools slowly underground the crystals are large enough to see.  Granite is an igneous rock and contains mainly quartz and feldspars.  Because of this, granites are mostly white, gray or pink with flecks of black, silver or brown.  The crystals are randomly placed and of equal size and the stone does not have layers or veins.  The slower the stone cools, the larger the crystals are.  Granite is a very dense stone and is impervious to acids.  This makes granite a superb choice for high traffic areas, outdoor applications or kitchen counter tops.

Metamorphic Rock


These stones are formed when sedimentary rock is changed by great heat or pressure, or both. The pressure can come from being buried very deep in the earth's crust, or from the huge plates of the earth's crust pushing against each other. The deeper below the surface of the earth, the higher the temperature, so deep burial also means high temperatures. Another way that high temperatures occur is when magma rises through the earth's upper crust. It is very hot and bakes the rock through which it moves. Hot liquids or gases from the magma also can cause chemical changes in the rock around the magma. Gneiss, schist,travertine and marble are metamorphic rocks and make up the bulk of commercially available stone slabs. The hardness and density of these materials fall between those of the igneous rocks and the sedimentary rocks, therefore making these materials suitable for a variety of uses around the house.

Sedimentary Rock


This rock forms from particles, called sediment, that are worn off other rocks. The particles are sand, silt, and clay. Sand has the largest particles while clay has the smallest. If there are a lot of pebbles mixed with the sand, it is called gravel. The sediment gets turned into rock by being buried and compacted by pressure from the weight above it. Another way it becomes rock is from being cemented together by material that has been dissolved in water.  Often, both cementing and compaction take place together. Limestone and sandstone are sedimentary rocks. They are softer than the other types of rock and are very porous. Sedimentary rocks often have fossils embedded in them and are very ornate. Quite often, sedimentary rock would react to acids, making them a poor choice for kitchens. These stones are best left for decorative purposes and should be handled carefully.

Before finally deciding on a certain material for your kitchen or bathroom, obtain a sample and thoroughly test it to determine its suitability

Gold & Silver Bourgogne Marinace

Stone Study


In 1999 the Hospitality Institute of Technology and Management did a test to compare the cleanliness and cleanability of various popular counter surfaces. Natural stone performed very well. The link above will take you to a page with more information about this study.

Test Your Stone


An easy-to-do couple of tests to find out if your stone needs sealer and whether it would react to acids.