LimestoneWritten by Joey Lewitin
Limestone is one of most versatile stones available. In its pure form it is hard enough to be used in almost any application, however it is relatively soft compared to other building stones such as marble.
Forms of limestone include chalk (a much softer version), and marl (a type of fertilizer). Travertine is also a limestone, though harder. Travertine is often found in stalactite and stalagmites that have formed in caves.
Limestone is chiefly composed of calcium carbonate. It is a sedimentary rock, which means that it is formed by collection of other minerals coming together to bond at a structural level. This most commonly occurs when lime builds up in oceans, then washes ashore and dries out.
It is white in its purest form; however impurities that become stuck in structure during formation cause colorful streaks and shades to appear in its surface. There are literally an unlimited number of colors limestone can come in due to variety of impurities and nature of their relationship to forming stone. Iron will generally cause colors in limestone to shift to red, or yellow, while carbon will shift colors more towards grey or black. The erratic nature of way impurities join with limestone, means that each piece of limestone is unique. Despite these wide variations Limestone can be easily categorized into several subgroups.
Travertine Written by Joey Lewitin
Travertine is one of most beautiful, versatile, and historically important stones. Its durability makes it highly useful in building applications, and it has been used in this manner since Roman Empire.
Formation Travertine is a form of limestone that is heavily compacted. Generally it is formed when minerals in streams or hot spring water become deposited on river beds and dry out. If chemical composition has enough of mineral calcium carbonate in it, then result is considered to be travertine.
Coloration In its purest form travertine is a very pale color, however imperfections in its structural make up, such as presence of iron, can cause beautifully colorful banding to occur across its face. Different colors are caused by different minerals, and different shapes are formed in stone dependant on how impurity combines with its structure. Since imperfections show up semi-randomly, no two pieces ever look exactly alike. It is however grouped into quarry names where similar strains of marble taken from similar places are classified into categories.