Where is black marble found

marble

Author: Torsten Purle (steine-und-minerale.de) | Last updated: 02/26/2021


Marble - properties, formation and use

English: marble | French: marbre



Marble - a shimmering metamorphite

The name marble is derived from ancient Greek mármamos - the word for shimmering or shining - and refers to the shimmering surface of the rock.



Properties of marble

definition: Marble is a metamorphic rock that consists of at least 50 percent by volume of the minerals calcite, dolomite or aragonite.

Chlorite, epidote, mica, limonite, garnet, pyrite, quartz and serpentine are possible secondary components, which make up up to five percent of the mineral composition of marble.



The color of marble depends on the mixture parts, i.e. the mineral components, and can white, gray, creamy white, red, green and blue be.

The characteristic feature of marble is the so-called. Marbling, which can be present in the form of light and dark stripes running through the rock, grains, spots or veins and are an expression of the mineral admixtures.
Variations: green, blue, gray and olivine marble.

The grain size of the aggregates in marble varies between coarse and fine, at the same time the mineral components of marble are stored very compactly. The texture is crystalline and marble is only translucent at the stone edges, but it always depends on the regulation and size of the mixed parts and the mineral purity.

According to the mineralogist Friedrich Mohs (1773 to 1839), marble is a soft rock with a hardness of 3 on the 10-point scale of the hardness of minerals and rocks, the density is 2.7 to 2.9 g / cm3.



Origin and distribution of marble

Marble is a rock of metamorphic origin. As a result of high temperature and pressure conditions during the formation, the original rock - carbonate-rich rock such as limestone or dolomite - is transformed in mineral composition, structure and appearance.

The typical marbling is evidence of the rock metamorphosis, whereby the reshaping of the parent rock can take place under both contact and regional metamorphic conditions.

In the course of Regional metamorphosis are the original rocks as a result of tectonic processes or the pressure load on overlying rock layers transformed. This process takes place over many millennia. The marble created accordingly shows one Directional structure on.

During the Contact metamorphosis cause in the earth's crust intruding magmasthat the surrounding rock to temperatures between 700 to 1100 ° C heated and melted becomes. The pressure is up to 10 kbar. The existing rocks and minerals cannot withstand these conditions and are partially or completely melted and then recrystallize, with numerous new minerals being created; First and foremost, mica - the parade mineral that is formed under metamorphic conditions.

Marble is common all over the world. There are significant deposits of marble in Spain, for example; Pas de Calais / France; Fichtel Mountains, Bavarian Forest, Odenwald / Germany; Kristall / Austria; Euboea Island, Drama, Kavala; Thassos / Greece; Turkey; Ticino, Valais / Switzerland; Tuscany, South Tyrol / Italy; Portugal; Devonshire / England.


Use and importance of marble

Marble is a sought-after natural stone that is used in interior design as well as for cladding facades, as flooring, sanitary facilities, worktops, ornamentation and as a whiskey stone for cooling whiskey.
Significant works of art from history such as the Acropolis, Michelangelo's David, the Obelisk from Washinton / USA and the Pergamon Altar are made of the natural stone marble.
Finely ground or powdered, marble is also used as an abrasive in toothpaste or scouring milk / abrasive sand / scouring powder and as a pigment in paints.


proof

When it comes into contact with acids, marble foams up.


See also:
⇒ antique marble
⇒ marble or travertine?
⇒ Moqui Marbles


Swell:
⇒ Pellant, C. (1994): Stones and Minerals. Ravensburger nature guide. Ravensburger Buchverlag Otto Maier GmbH ⇒ Schumann, W. (1991): Minerals rocks - characteristics, occurrence and use. FSVO nature guide. BLV Verlagsgesellschaft mbH Munich
⇒ Maresch, W., Medenbach, O .; Trochim, H.-D. (1987): The colored natural guide rocks. Mosaik Verlag GmbH Munich
⇒ Murawski, H. (1992): Geological Dictionary. Ferdinand Enke Verlag Stuttgart
⇒ Schumann, W. (1994): Collecting stones and minerals; find, prepare, determine. BLV Verlag Munich