What is Ophitic texture?

Asked By: Gitta Encinar | Last Updated: 24th May, 2020
Category: science geology
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Ophitic texture is the association of lath-shaped euhedral crystals of plagioclase, grouped radially or in an irregular mesh, with surrounding or interstitial large anhedral crystals of pyroxene; it is characteristic of the common rock type known as diabase.

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Consequently, 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.

Subsequently, question is, 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.

Secondly, 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.

39 Related Question Answers Found

What is the texture of gabbro?

Gabbro is mafic, intrusive, coarse-grained rock with allotriomorphic texture. Gabbros contain mainly ferromagnesian minerals and plagioclase, the amount of ferromagnesian minerals equaling or exceeding that of the plagioclase.

What is Corona texture?

A Corona is a zone of minerals, usually with radial arrangement, around another mineral. A change in metamorphic conditions can give rise to porphyroblast growth, or to partial replacement of some minerals by others. Such replacement usually occurs along grain boundaries and causes development of reaction rims.

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.

What is the texture of igneous rocks?

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.

Where is norite found?

Norite is a common rock type of the Apollo samples. On a smaller scale, norite can be found in small localized intrusions such as the Gombak norite in Bukit Batok, Singapore. It is also plentiful in the Egersund intrusion area of southwestern Norway, with titanium deposits to the east.

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.

Is Augite a pyroxene?

Augite is a common rock-forming pyroxene mineral with formula (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6. The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees.

What is the Bowen reaction series and how does it work?

Bowen's reaction series can be defined as the crystallization sequence of magma as cooling occurs. It has two parts, the discontinuous series and the continuous series. Both branches progress with a drop in temperature. As crystals solidify in the magma, they sink and settle out of the liquid magma.

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 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 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 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.

How do you classify a rock?

Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. These physical properties are the result of the processes that formed the rocks.

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 a crystalline texture?

Texture (or rock microstructure) in geology refers to the relationship between the materials of which a rock is composed. Crystalline textures include phaneritic, foliated, and porphyritic. Phaneritic textures are where interlocking crystals of igneous rock are visible to the unaided eye.

What does Equigranular mean?

: having or characterized by crystals of nearly the same size a rock of equigranular texture.