Graphic texture

{{Short description|Texture in igneous rocks}}

File:SKRIFTGRANITT 02 Einerkilen-Evje.jpg

File:SKRIFTGRANITT 03 Einerkilen-Evje.jpg

File:Graphic granite, southwestern Kola Peninsula Russia.jpg

Image:Graphic-texture.jpg

Graphic texture is commonly created by exsolution and devitrification and immiscibility processes in igneous rocks.

It is called 'graphic' because the exsolved or devitrified minerals form lines and shapes which are reminiscent of writing.

Graphic granite is a leucocratic granitic rock consisting of alkali feldspar with exsolved quartz typically forming a distinctive repetitive pattern sometimes resembling cuneiform writing. Experiments have shown that graphic granite texture is derived from large single crystals of quartz and feldspar interleaving to create the cuneiform illusion.[http://www.minsocam.org/ammin/AM71/AM71_325.pdf Fen, Philip M., 1986, On the Origin of Graphic Granite, American Mineralogist, Vol. 71, pp. 325-330]

Exsolved magnetite has graphic texture, as do some exsolution textures of pyroxene, pyrite feldspar and rarely other minerals.