Forbach Granite (german: Forbachgranit), also called Raumünzach Granite (''Raumünzach-Granit''), is a type of

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...

rock that occurs in the

Northern Black Forest The Northern Black Forest (german: Nordschwarzwald) refers to the northern third of the Black Forest in Germany or, less commonly today, to the northern half of this mountain region. Geography The Northern Black Forest is bounded in the north b ...

. It is part of the Northern Black Forest's granitic massif, to which Bühlertal granite and Wildbad granite also belong. Forbach granite predominantly outcrops in the counties of

Calw Calw (; previously pronounced and sometimes spelled ''Kalb'' accordingly) is a town in the middle of Baden-Württemberg in the south of Germany, capital and largest town of the district Calw. It is located in the Northern Black Forest and is a ...

and

Rastatt Rastatt () is a town with a Baroque core, District of Rastatt, Baden-Württemberg, Germany. It is located in the Upper Rhine Plain on the Murg river, above its junction with the Rhine and has a population of around 50,000 (2011). Rastatt was an ...

. The most important quarrying area for Forbach granite used to be the middle Murg valley near

Forbach Forbach ( , , ; gsw, Fuerboch) is a commune in the French department of Moselle, northeastern French region of Grand Est. It is located on the German border approximately 15 minutes from the center of Saarbrücken, Germany, with which it co ...

. Today it is only

quarried A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environ ...

near

Raumünzach Forbach ( , ) is a village and municipality in Baden-Württemberg, Germany. It lies in the district of Rastatt. It is located in the Murg river valley, in the northern part of the Black Forest mountains. Forbach is further broken down into the ...

. Forbach Granite is about 305 million years old. The stone is coarse-grained - this points to a slowly cooling of the lava / magma (at the time the formation of the stone). Forbach Granite is a bright

mica Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is ...

, coloured from gray to pink. Forbach Granite includes the following minerals. * Alkali feldspars (up to 44 percent) have a size of up to 5 centimetre and leads to a red colour. *

Quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...

(26 percent). *

Plagioclase Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more pro ...

(20 percent) *

Muscovite Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula K Al2(Al Si3 O10)( F,O H)2, or ( KF)2( Al2O3)3( SiO2)6( H2O). It has a highly perfect basal cleavage ...

(5 percent) *

Biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron- endmember annite, and the magnesium-endmember phlogopite; more alum ...

(5 percent) and leads to the distinct structured texture. *

Apatite Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common ...

(below 1 percent) *

Monazite Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the ceriu ...

(rare) *

Xenotime Xenotime is a rare-earth phosphate mineral, the major component of which is yttrium orthophosphate ( Y P O4). It forms a solid solution series with chernovite-(Y) ( Y As O4) and therefore may contain trace impurities of arsenic, as well as si ...

(rare)

Literature

* W. Dienemann und O. Burre: ''Die nutzbaren Gesteine Deutschlands und ihre Lagerstätten mit Ausnahme der Kohlen, Erze und Salze,'' Enke-Verlag, Stuttgart, 1929, p. 2 * Otto Franz Geyer, Manfred P. Gwinner: ''Geologie von Baden-Württemberg''. 3rd fully revised edition, Schweizerbart, Stuttgart, 1986, . * Wolf-Dieter Grimm: ''Bildatlas wichtiger Denkmalgesteine der Bundesrepublik Deutschland.'' Published by the Bayerischen Landesamt für Denkmalpflege, Lipp-Verlag, Munich, 1990, , Rock no. 011.

External links

Geological Natural Monuments in the Province of Karlsruhe (''Geologische Naturdenkmale im Regierungsbezirk Karlsruhe'')
(pdf, 5.6 MB)
Quarry in Raumünzach
* {{Commons category-inline, Forbachgranit, Forbach Granite South German Scarplands Granite Rastatt (district) Calw (district) Geology of Germany