Romans. The name, from the Greek word marmairein (to shine), is correctly applied to limestones, which are essentially composed of carbonate of lime, and capable of being used as decorative stones. The larger class of these marbles are metamorphic; that is, they have been transformed from non-crystalline to crystalline rocks. This change is usually caused by earth movement accompanied by heat and pressure. Of limestones from which the greater part of marble is derived there are two varieties, the most common being formed of the hardened calcareous remains of plants and animals, that is, of organic origin. The other variety is of inorganic formation, and is deposited by water carrying carbonate of lime in solution, thus forming sheets of limestone. Of such is the ordinary compact limestone. It is difficult to ascertain from which of these two formations a marble may be derived, as in crystallization all fossil remains are often entirely obliterated.
Description:
Romans. The name, from the Greek word marmairein (to shine), is correctly applied to limestones, which are essentially composed of carbonate of lime, and capable of being used as decorative stones. The larger class of these marbles are metamorphic; that is, they have been transformed from non-crystalline to crystalline rocks. This change is usually caused by earth movement accompanied by heat and pressure. Of limestones from which the greater part of marble is derived there are two varieties, the most common being formed of the hardened calcareous remains of plants and animals, that is, of organic origin. The other variety is of inorganic formation, and is deposited by water carrying carbonate of lime in solution, thus forming sheets of limestone. Of such is the ordinary compact limestone. It is difficult to ascertain from which of these two formations a marble may be derived, as in crystallization all fossil remains are often entirely obliterated.