Mica Content In Granite

The mica group of sheet silicate phyllosilicate minerals includes several closely related materials having nearly perfect basal cleavage all are monoclinic with a tendency towards pseudohexagonal crystals and are similar in chemical composition the nearly perfect cleavage which is the most prominent characteristic of mica is explained by the hexagonal sheet like arrangement of its atoms.

Mica content in granite. A worldwide average of the chemical composition of granite by weight percent based on 2485 analyses. The granite we picked comes with a little mica or a lot of mica but by chance we ended up with a slab that had a lot. Granite is composed mainly of quartz and feldspar with minor amounts of mica amphiboles and other minerals this mineral composition usually gives granite a red pink gray or white color with dark mineral. It forms from the slow crystallization of magma below earth s surface.

A granite containing both muscovite and biotite micas is called a binary or two mica granite. It s mined around the world including india brazil norway italy and china. The largest granite quarry in the united states is near barre vermont. Granite problem with mica content.

Two mica granites are typically high in potassium and low in plagioclase and are usually s type granites or a type granites. Two mica granite aberdeen. Learn from our experience with granite and you might avoid the problems we encountered. Granite is a igneous rock containing at least 20 quartz by volume but also some mica and feldspar.

Many of the civic buildings in the local city of aberdeen were built from this granite which comes from the rubislaw quarry.