other names: Marble
mineral class: Carbonates
chemical formula: CaCO3
Chemical elements: Calcium, carbon, oxygen
Similar minerals: Limestone
colour: in pure form with white coloring
crystal structure: ?
mass density: approx. 2.7
magnetism: not magnetic
Mohs hardness: 3
stroke color: White
use: Building material
General to the marble:
marble describes a metamorphic rock type which is composed of at least fifty percent dolomite, aragonite or calcite. In addition to these main constituents admixtures of different minerals such as quartz, pyrite, mica, garnet, serpentine or limonite are possible. The name marble is derived from the ancient Greek word "máramos", which means "shine" or "shimmer" and refers to the appearance of the surface of the rock. Depending on the chemical additives, marble appears in different shades, ranging from pure white to cream and light gray to red, green and black. The color red is due to admixtures of hematite, a greenish color of the marble is formed by the action of chlorite or serpentine. Silver varieties are mostly due to Muskovit admixtures, black marble has shares of graphite, manganese or marcasite. All varieties of marble share the characteristic marbling, which can be seen in delicate stripes, stains, grains and other patterns. Marble has a crystalline structure and, with a Mohs hardness of 3, is one of the soft rock types. The individual crystals, which are made of calcite, differ greatly in size and shape and are clearly visible to the naked eye in most species. Fine-crystalline varieties such as the world-famous Carrara marble are highly prized among artists. The otherwise opaque rock may be delicately translucent at the edges. Contact with acid causes the marble to foam.
Origin, occurrence and localities:
Marble develops in the interior of the earth under high pressure conditions and temperatures of at least 400 ° C from carbonate-rich rocks such as dolomite or limestone, which receive a characteristic marbling in the course of a contact or regional metamorphosis by chemical admixtures. Often, marble forms in the course of tectonic shifts, fly through the large boulders and exert a strong pressure from above.
Marble looks back on a long history of mining in Europe and is still being mined on a grand scale, especially in Greece and the Tuscan city of Carrara. Today, mainly state-of-the-art iron wedges and formatting blocks are used. In addition to Italy and Greece, northern Italy, Austria, Germany and Switzerland, France, Turkey and the coast of the south English county of Devon are of great importance for the extraction of marble.
History and use of marble:
Since antiquity, marble has been a sought-after material for the manufacture of buildings, statues and wall coverings, floor coverings and sculptural interior decorations. Not only from the Roman Empire and ancient Greece are world-famous marble works of art, also in the Renaissance and modern times, numerous works of famous Artist and sculptor attained historical significance. Today, bathrooms made of marble, floor coverings, washbasins and wall tiles are highly sought after, with Carrara marble being the preferred building material. As the natural stone reacts extremely sensitively to acids, vinegar and aggressive cleaning products with chemical and natural additives, it is only conditionally suitable for the production of countertops and sinks in kitchens. In powder form, marble is also of great importance as an additive to toothpaste, as a white color pigment in plasters and stains, and as a filler in paper.