What is Intergrowth texture?

Asked By: Ilidia Jidilev | Last Updated: 22nd April, 2020
Category: science geology
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A graphic texture is an igneous rock texture in which an intergrowth of two minerals has the appearance of runic writing. Graphic textures are most commonly intergrowths of quartz and alkali feldspar in which the quartz appears as v-shaped inclusions enclosed by the feldspar.

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Similarly, what is Perthitic texture?

A perthite is an intimate intergrowth of sodic and potassic feldspar resulting from subsolidus exsolution (unmixing of two minerals). An Antiperthite is an intergrowth arising due to exsolution where potassic feldspar is present as blebs or lamellae within a sodic feldspar.

One may also ask, what is Panidiomorphic texture? Definition of hypidiomorphic texture. A texture of igneous rocks in which the greater proportion of the crystallized minerals have subhedral forms.

Then, how do you describe the texture of a rock?

The texture of a rock is the size, shape, and arrangement of the grains (for sedimentary rocks) or crystals (for igneous and metamorphic rocks). Also of importance are the rock's extent of homogeneity (i.e., uniformity of composition throughout) and the degree of isotropy.

What is the texture of pegmatite?

A pegmatitic texture is one in which the mineral grains are exceptionally large. The largest ones are, by convention, more than about 3 cm long. This texture is found in intrusive rocks. Instead, the large crystals of a pegmatite formed in a magma that was extra rich in dissolved water.

37 Related Question Answers Found

What is Poikilitic texture?

Poikilitic texture refers to crystals, typically phenocrysts, in an igneous rock which contain small grains of other minerals. In igneous rocks Poikilitic texture is widely used to determine order of crystallization; if one mineral is enclosed by another then the enclosed grain must have been the first to crystallize.

What is Exsolution?

Exsolution is a process by which a solid solution phase unmixes into two separate phases in the solid state. Exsolution occurs only in minerals whose compositions vary between two or more pure endmember compositions.

What is Trachyte used for?

Texture - generally porphyritic (can be trachytic), sometimes aphanitic. Mineral content - orthoclase phenocrysts in a groundmass of orthoclase with minor plagioclase, biotite, hornblende, augite etc.. Silica (SiO 2) content - 60%-65%. Uses - building and paving stone; dimension stone for building facings, foyers etc.

Which texture is typical of granite?

Granites are intrusive felsic rocks (from the Latin “granum” means “grain”) usually hypidiomorphic (greater proportion of subhedral crystal forms) and typically granular texture (Fig. 4.6(A)). The grain size varies between fine (Figs 4.10 and 4.11), medium and coarse.

What is potassium feldspar?

Potassium feldspar refers to a number of minerals in the feldspar group, and containing potassium: Orthoclase (endmember formula KAlSi3O8), an important tectosilicate mineral that forms igneous rock. Microcline, chemically the same as orthoclase, but with a different crystalline structure.

Which feldspar has exsolution lamellae?

Perthite is used to describe an intergrowth of two feldspars: a host grain of potassium-rich alkali feldspar (near K-feldspar, KAlSi3O8, in composition) includes exsolved lamellae or irregular intergrowths of sodic alkali feldspar (near albite, NaAlSi3O8, in composition).

Does feldspar have cleavage?

Feldspars have two cleavage planes that intersect at 90°. Fragments of pure feldspar crystals thus tend to form rectangular blocks with irregular ends. Feldspars have vitreous lusters and occur in opaque shades of white to gray to pink to very dark gray.

What are the 4 types of texture?

The texture stimulates two different senses: sight and touch. There are four types of texture in art: actual, simulated, abstract, and invented texture.

What is the texture of stone?

Types of Surface Textures stones. A slightly rough texture that is achieved by tumbling small pieces of marble, limestone, and sometimes granite to achieve an archaic/worn appearance. It often requires an application of Stone Color Enhancer to bring out the colors.

What are the 6 characteristics of a rock?

The following properties are very useful for identification purposes:
  • Hardness.
  • Cleavage.
  • Luster.
  • Color.
  • Streak rock powder.
  • Texture.

What is the texture of this sedimentary rock?

Unlike igneous crystalline textures, however, sedimentary crystalline textures are typically formed from one mineral throughout the entire rock. Microcrystalline texture: no crystals are visible but the rock is composed of interlocking microscopic crystals. Such rocks are dense and typically nonporous.

What is a mineral's texture?

Texture refers to the size, shape and arrangement of grains of one or more. minerals which make up the ore or rock. In rocks the features that determine. the texture are: crystallinity, granularity and fabric; however, ore minerals.

What are examples of textures?

Examples of physical texture
  • Berlin Green Head, 500BC.
  • Detail of woven fibers of a carpet.
  • Animals are often defined by their physical texture, such as a fuzzy kitten or this scaly iguana.
  • Blades of grass provides a soft texture.
  • Rough bark on the surface of a tree.
  • A wall of bricks with raised areas.

What is the texture of a igneous rock?

Igneous textures include the rock textures occurring in igneous rocks. Igneous textures are used by geologists in determining the mode of origin igneous rocks and are used in rock classification. There are six main types of textures; phaneritic, aphanitic, porphyritic, glassy, pyroclastic and pegmatitic.

What factors can affect the texture of an igneous rock?

The main factors that can affect the texture of an igneous rock are the location and cooling rate of the hot magma that forms the rock.

What is porphyritic texture?

Porphyritic texture is a very common texture in igneous rocks in which larger crystals (phenocrysts) are embedded in a fine-grained groundmass. Porphyry is an igneous rock that contains larger crystals (phenocrysts) in a fine-grained groundmass. K-feldspar phenocrysts in this sample.