How does biotite alter to chlorite?
Abstract. Granitic biotite from southeastern Australia alters to a mixture of chlorite (65%), sphene (10%) and epidote (10%) through a hydrothermal (330–340°C) reaction in which two layers of biotite become one layer of chlorite.
What do muscovite and biotite have in common?
What do muscovite and biotite have in common? How do they differ? They are both micas with layered (sheet-silicate), internal, crystalline structures and one direction of perfect cleavage.
What’s the difference between muscovite and biotite?
Muscovite is clear, silvery, or coppery silver in color (depending on the thickness of the sample and presence of impurities) whereas fresh biotite is black. When biotite weathers, it can become dark golden or coppery in color.
What metamorphic rock contains chlorite and biotite?
Types of Schist and Their Composition As explained above, mica minerals such as chlorite, muscovite, and biotite are the characteristic minerals of schist.
What is chlorite alteration?
At Xiaokelehe, chlorite-illite alteration is characterized by chlorite, illite, disseminated chalcopyrite and pyrite assemblages that are widely developed in the granodiorite porphyry. The illite is altered from plagioclase or K-feldspar, and the chlorite from both igneous and hydrothermal biotite.
What is chlorite mineral used for?
|Physical Properties of Chlorite|
|Uses||Very few industrial uses. Used as a filler and as a constituent of clay.|
What are the two members of the mica family and how can you distinguish between the two of them?
Physical properties The rock-forming micas (other than glauconite) can be divided into two groups: those that are light-coloured (muscovite, paragonite, and lepidolite) and those that are dark-coloured (biotite and phlogopite).
Are mica and muscovite the same thing?
muscovite, also called common mica, potash mica, or isinglass, abundant silicate mineral that contains potassium and aluminum. Muscovite is the most common member of the mica group. Because of its perfect cleavage, it can occur in thin, transparent, but durable sheets.
Where is chlorite found?
They are found in igneous, metamorphic and sedimentary rocks. Chlorite minerals are found in rocks altered during deep burial, plate collisions, hydrothermal activity, or contact metamorphism. They are also found as retrograde minerals in igneous and metamorphic rocks that have been weathered.
What are the two types of metamorphic rocks?
There are two main types of metamorphic rocks: those that are foliated because they have formed in an environment with either directed pressure or shear stress, and those that are not foliated because they have formed in an environment without directed pressure or relatively near the surface with very little pressure …
Is chlorite a mica?
Chlorite is a member of the mica group of minerals (sheet silicates), like biotite and muscovite. Chlorite is widespread in low grade metamorphic rocks such as slate and schist, in sedimentary rocks, and as a weathering product of any rocks that are low in silica (especially igneous rocks).
Is biotite and muscovite the same thing?
Biotite is another common mica mineral with a single perfect cleavage similar to that of muscovite. The two often occur together in the igneous and metamorphic rocks, but they can be distinguished by their color. Muscovite is very light colored to colorless, while biotite is much darker (typically brown to black).
Is muscovite a silicate?
Muscovite Muscovite is a member of the mica group of silicate minerals (sheet silicates) in which the base of all of the SiO 4 tetrahedra lie in one plane and three corners of the base are shared with the neighbouring tetrahedra.
What are muscovite flakes used for?
Muscovite flakes are used to create the sparkle seen in artificial snow for Christmas decorations and the glitter of many cosmetic products such as nail polish, glitter, glossy lipstick and shimmering eye shadow.