All those textures in which majority of constituent crystals of a rock are broadly equal in size are described as equigranular textures. In igneous rocks, these textures are shown by granites and felsites and hence are also often named as granitic and felsitic textures.

Nov 5, 2019 · There are nine main types of igneous rock textures: Phaneritic, vesicular, aphanitic, porphyritic, poikilitic, glassy, pyroclastic, equigranular, and spinifex. Each kind of texture has a variety of different characteristics that make them unique.

Equigranular texture: Equigranular rocks have mineral grains that are all approximately the same size and shape. Spinifex texture: Spinifex rocks are characterized by needle-shaped crystals that are arranged in radiating bundles.

Mar 6, 2025 · Even-grained, or equigranular, rocks are characterized by essential minerals that all exhibit the same order of grain size, but this implied equality need not be taken too literally.

For example, a rock can be phaneritic and equigranular if you can see all of its grains and they are all approximately the same size. Once you have determined your rock’s texture you can use that description, along with its general mineral composition, to properly identify your rock.

Rocks may be equigranular or inequigranular, with those that exhibit the presence of relatively large crystals ( phenocrysts, megacrysts) in a finer-grained groundmass (matrix, mesostasis) referred to as having porphyritic texture.

Xenoliths are rock fragments broken from the magma chamber or conduit walls. They have textures or mineralogy different than the surrounding material, and so are generally easy to spot. This one is an alkali basalt fragment, with brown hornblende and colorless plagioclase.

Textures are penetrative fabrics of rocks; they occur throughout the entirety of the rock mass on microscopic, hand-sized specimen, and often outcrop scales. This is similar in many ways to foliations, except a texture does not necessarily carry structural information in terms of deformation events and orientation information.

Granoblastic texture is the typical equigranular texture formed in metamorphic rocks when grains mutually adjust their boundaries in the solid state in an attempt to achieve textural equilibrium.

1. Equigranular: In this texture the minerals of the rock are more or less equal in size. 2. Inequigranular: The mineral of the rock will be of different sizes. Three important textures of inequigranular texture are: (a) Porphyritic textures, (b) Poikitic texture, and (c) Ophitic texture. (a) Porphyritic texture: Bigger grains surrounded by ...