Stone

Stones are the result of sedimentation of minerals for many years. So, they have a long process to form themselves. I actually don´t know how to differentiate stones scientifically, but I __suppose__ that has something to do with their chemical and __physical__ composition, with the different ways they were __formed__ along the centuries. Therefore, in consequence of my lack of knowlege, I only can __separate__ one stone from another based on their __physical__ characteristics, like for exemple, color, shape, resistance, __etc.__

Although, I can __mention__ a few characteristics of stones, they usually are really tough, condition that has led us to use them in constructions, especially at the beginning of our civilitation and, depending __on__ the stone, they can be shaped without crack. However, it´s a material very difficul to transport and __limits__ the form of the construction, because it´s not very stable. Thus, nowadays, stone is usually used for decoration insted of basic structure.

** Stones, like any other construction material, have their advantages and disadvantages. On their advantages it can be mentioned their adaptability to sculptural treatment, their resistance to extern elements, therefore stone constructions are durable among years and it isn’t needed a long and complicated process to use it. I believe, this last one, __is__ the main reason why our ancestors chose stone as primarily material to large constructions like, for example, Stonehenge. On the other hand, we have that stone is very difficult to transport among places, isn’t a malleable material and doesn’t support much tension. All these have led us to reserve stone as a decorative element and use other modern materials. **
 * There are two kinds of stones, the first and cheapest one __is__ rubble; __they__ are diverse broken stones that are bonded in mortar. Also, we have ashlar masonry, which __is__ the perfect stone for monumental constructions, due to __its__ weight, regular form and because __of its__ similar blocks, they can be placed with good precision .  **  
 * In ancient times stone was used for all the important constructions, as an example of this we have the remains of Greek, Roman, Egyptian, __etc__. architecture. However, with the pass of years we have evolved and nowadays manufactured and cheaper materials are used in construction instead of ston e.   **