What is exsolution lamellae in geology?
Exsolution is a process by which a solid solution phase unmixes into two separate phases in the solid state. These lamellae result from the exsolution of a separate pyroxene phase from a host grain due to subsolidus re-equilibration (that occurs while the mineral is in the solid state) during slow cooling.
Which mineral has the exsolution lamellae structure?
pyroxene structure The lamellae are exsolved along specific crystallographic directions, producing oriented intergrowths with parallel and herringbone texture.
What is Perthitic exsolution?
A perthite is an intimate intergrowth of sodic and potassic feldspar resulting from subsolidus exsolution (unmixing of two minerals). An antiperthite is an intergrowth arising due to exsolution where potassic feldspar is present as blebs or lamellae within a sodic feldspar.
Does potassium feldspar have lamellae?
Potassium feldspar (also orthoclase feldspar or K-spar) exhibits bands of different color on cleavage surfaces. These bands, or exsolution lamellae, are planar zones of slightly different composition.
What are the lamellae?
A lamella (plural: “lamellae”) in biology refers to a thin layer, membrane or plate of tissue. This is a very broad definition, and can refer to many different structures. All the thylakoids of a granum are connected with each other, and the grana are connected by intergranal lamellae.
What are perthite and antiperthite?
What is the Colour of feldspar?
As indicated by the fact that they lack inherent colour, feldspars can be colourless, white, or nearly any colour if impure. In general, however, orthoclase and microcline have a reddish tinge that ranges from a pale, fleshlike pink to brick-red, whereas typical rock-forming plagioclases are white to dark gray.
What is lamellae and its function?
Stroma lamellae connect thylakoids of two different grana. They increase the efficiency of photosynthesis by keeping grana at a distance so that they do not clutter together. They are also known as stroma thylakoids. They ensure that maximum energy from sunlight is captured in photosynthesis.