Granite
                 The name "granite" is used to cover a group of related stones which originate deep in the earth's molten mantle. As this extremely hot liquid material rises and cools, it forms a crystaline, granular structure; hence the name "granite". Granite and other granite-like stones are formed of hard minerals such as quartz, feldspar and mica, which are fused together into a very hard stone, which is ideal for kitchen counters. It's polish is resistant to household acids such as citrus and vinegar, and it is hard enough to resist scratching from knives,  pots and pans.

Marble
                 True geological marble is limestone that has been subjected to great pressure and heat, which has changed its structure to a crystalline, sugary texture. It is generally white or off-white, sometimes translucent, with some veining or color provided by other minerals present at its formation. Commercially, the term "marble" apllies to any compact limestone that will take a polish, which includes most of the colored marbles, except for some of the green-colored types.

Limestone
                 Limestone is a sedimentary rock consisting mostly of organic materials such as skeletons and shells of marine creatures and sediments. It is formed by material which settles to the bottom of bodies of water. Over millions of years it solidifies (lithifies) into solid rock.

Travertine
                 Travertine is a limestone formed by geysers like Old Faithful. When the geyser erupts, it carries a mixture of extremely hot water and limestone particles out through the opening in the surface of the earth. When the water falls to the ground and evaporates, it leaves behind the dissolved limestone, which re-hardens into stone. The new stone is full of air pockets from gas bubbles, which gives Travertine it's characteristic appearance.