Textures - Grain Size Basis

Phaneric Texture

When igneous rocks whose mineral grains are seen without any ailments by the naked eye, it is said to be phaneric texture

Coarse Grained

When the diameter of the mineral grain is more than 5 mm, it is said to be coarse grained. Most of them are intrusive or plutonic rocks.

Medium Grained

When the diameter of the grain size is between 1 - 5 mm, it is said to be medium grained.

Fine Grained

When the diameter of the grains are less than 1mm, it is said to be fine grained. They are mostly extrusive and volcanic rocks.

Aphanitic

Mineral grains which cannot be seen under the naked eye are called as Aphanitic Texture

Microcrystalline Texture

Microcrystallline texture is the condition when the mineral grains can be distinguished under microscope.

Cryptocrystalline Texture

Cryptocrystalline crystals are very small to seen under microscope. The presence can be identified by the use of polarized light

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