Metamorphic Black Marble Rock

Slate is another common metamorphic rock that forms from shale.

Metamorphic black marble rock.

Although metamorphic rocks typically form deep in the planet s crust they are often exposed on the surface of the earth. The variety of colours exhibited by marble are a consequence of minor amounts of impurities being incorporated with the. Foliated metamorphic rocks such as gneiss phyllite schist and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure. It is composed primarily of the mineral calcite caco 3 and usually contains other minerals such as clay minerals micas quartz pyrite iron oxides and graphite under the conditions of metamorphism the calcite in the limestone recrystallizes to form a rock that is.

Marble forms under such conditions because the calcite forming the limestone recrystallises forming a denser rock consisting of roughly equigranular calcite crystals. Non foliated metamorphic rocks such as hornfels marble quartzite and novaculite do not have a layered or banded appearance. Metamorphic rock any rock that results from the alteration of preexisting rocks in response to changing conditions such as variations in temperature pressure and mechanical stress and the addition or subtraction of chemical components. Marble is a metamorphic rock composed of recrystallized carbonate minerals most commonly calcite or dolomite marble is typically not foliated although there are exceptions in geology the term marble refers to metamorphosed limestone but its use in stonemasonry more broadly encompasses unmetamorphosed limestone.

Marble is a metamorphic rock that forms when limestone is subjected to the heat and pressure of metamorphism. The color of marble can range from the purest white to black ranging through the warmer colors in between depending on the other mineral impurities. Commercially it includes all decorative calcium rich rocks that can be polished as well as certain serpentines verd antiques. In its pure form marble is a white stone with a crystalline and sugary appearance consisting of calcium carbonate caco 3 usually marble contains other minerals including quartz graphite pyrite and iron oxides these minerals can give marble a pink brown gray green or variegated coloration.

The preexisting rocks may be igneous sedimentary or other metamorphic rocks. Marble is commonly used for sculpture and as a building material. Petrographically marbles are massive rather than thin layered and consist of a. Marble granular limestone or dolomite i e rock composed of calcium magnesium carbonate that has been recrystallized under the influence of heat pressure and aqueous solutions.

Like other metamorphic rocks marble has no fossils and any layering that appears in it probably does not correspond to the original bedding of the precursor limestone. Pictures and brief descriptions of some common types.