What rock has parallel alignment of mineral grains?

What rock has parallel alignment of mineral grains?

Foliated rocks
Foliated rocks are defined by the parallel alignment of mineral grains that are mostly thin and planar such as micas or in some cases hornblende.

What rocks have parallel bands of minerals?

Foliated Metamorphic Rocks: (Foliated means the parallel arrangement of certain mineral grains that gives the rock a striped appearance.)

What is an alignment of minerals called in a rock?

Foliation is the name given to the process of minerals becoming aligned.

What mineral has platy cleavage?

Platy cleavage (sheets). Streak white to gray. Schist, gneiss, granodiorite, granite*, rhyolite*. Used as an insulator and in electrical devices.

What is a platy mineral?

platy Applied to minerals which develop a crystal form consisting of thin, leaf-like layers. The mica group of minerals provides a good example; the mineral splits along cleavage planes which are parallel to rows of alkali atoms in the crystal structure. A Dictionary of Earth Sciences. “platy .”

Is quartz a platy mineral?

As the term implies, NON-FOLIATED rocks lack foliation or banding. Such rocks are most commonly composed of minerals that are neither platy nor needle-like, but rather more equidimensional (more or less the same dimension in all directions). Quartz, calcite and dolomite are the most common such minerals.

What are quartzite rocks?

quartzite, sandstone that has been converted into a solid quartz rock. Unlike sandstones, quartzites are free from pores and have a smooth fracture; when struck, they break through, not around, the sand grains, producing a smooth surface instead of a rough and granular one.

What is foliation and lineation?

Foliation is the result of the parallel arrangement of (micas, etc.) in a plane perpendicular to the maximum principal applied stress. A lineation is caused by a similar growth of elongate minerals (eg. hornblende) in this plane. Slate, schist, and gneiss are three common foliated metamorphic rocks.

What platy minerals often define the foliation of a metamorphic rock?

Metamorphic rocks with a foliation pattern defined by the layering of platy minerals are called schist; the rock name is commonly modified to indicate what mica is present. For example, Figure 5.4 is a photo of a muscovite schist, with garnet present, so the correct name for this rock is a garnet muscovite schist.

What is platy geology?

(of an igneous rock) split into thin, flat sheets, often resembling strata, as a result of uneven cooling.

What are platy materials?

Is muscovite a platy mineral?

In the convergent plate boundary environment, heat and chemical activity transform the clay minerals of shales and mudstones into platy mica minerals such as muscovite, biotite, and chlorite.

What causes mineral alignment in metamorphic rocks?

Metamorphic textures Foliation is caused by the re-alignment of minerals when they are subjected to high pressure and temperature. Individual minerals align themselves perpendicular to the stress field such that their long axes are in the direction of these planes (which may look like the cleavage planes of minerals).

Is foliation and banding same?

Banding means that the rock consists of alternating, thin layers (typically 1 mm to 1 cm) of two different mineral compositions. Normally, the two types of layers have the same kinds of minerals, but in different proportions, giving the rock a striped appearance. Banding, by itself, defines a foliation.

What minerals are in quartzite?

Quartzite: A granoblastic metamorphic rock consisting mainly of quartz (>90%) and formed by recrystallization of sandstone or chert by either regional or thermal metamorphism. Accessory minerals include feldspar, micas, and detrital heavy minerals such as titanite, magnetite, zircon and rutile.

How do you identify quartzite?

Here, quartzite is identified by the way it fractures across grain boundaries, while arenite breaks around them. Other geologists simply identify “quartzite” as a tightly-cemented rock found above or below a band of sedimentary quartz rock.