What type of rock is graphic?
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.
Where is graphic granite found?
granitic pegmatites
About Graphic graniteHide This is found almost exclusively in granitic pegmatites, and is believed to result from simultaneous growth of the feldspar and quartz under conditions which favored the planar growth of feldspar and the rods of quartz.
Which texture is shown by granite?
Granite is the plutonic equivalent of rhyolite. Group – plutonic. Colour – variable but typically light-coloured. Texture – phaneritic (medium to coarse grained).
What is graphic texture in geology?
Graphic texture refers to the regular intergrowth of two minerals, one of them generally serving as a host and the other appearing on surfaces of the host as striplike or cuneiform units with grossly consistent orientation; the graphic intergrowth of quartz in alkali feldspar is…
What is graphic quartz?
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. …
Is granite intrusive or extrusive?
intrusive igneous rock
Granite is an intrusive igneous rock. Intrusive rocks form from molten material (magma) that flows and solidifies underground, where magma cools slowly.
What is Spherulitic texture?
Spherulitic aggregate (pherulites) are radiating arrays of fibrous, needle-like or acicular, crystals that are common in glassy felsic volcanic rocks. Thus, in contrast to dendrites, spherulites are aggregate of separate crystals, rather than branched single crystals.
What is cumulate texture?
Cumulate rocks are igneous rocks formed by the accumulation of crystals from a magma either by settling or floating. Cumulate rocks are named according to their texture; cumulate texture is diagnostic of the conditions of formation of this group of igneous rocks.
What is a granite texture?
Granites usually have a coarse texture (individual minerals are visible without magnification), because the magma cools slowly underground, allowing larger crystal growth. Granites are most easily characterized as light colored and coarse grained as a result of cooling slowly below the surface.
Is granite smooth or rough?
A granite countertop of sufficient quality should feel as smooth as glass. What About Polishing the Surface? Some may suggest that the solution to a rough granite countertop surface is more polishing.
Does Macos still use quartz?
As of Mac OS X v10. 5 Quartz 2D Extreme has been renamed to QuartzGL. However, it still remains disabled by default, as there are some situations where it can degrade performance, or experience visual glitches; it is a per-application setting which can be turned on if the developer wishes.
What are pegmatites used for?
Pegmatite is often mined for industrial minerals. Large sheets of mica are mined from pegmatite. These are used to make components for electronic devices, retardation plates, circuit boards, optical filters, detector windows, and many other products. Feldspar is another mineral frequently mined from pegmatite.