Why Is Granite So Hard?

Why Is Granite So Hard?

Dec 02, 2020

Granite is not only hard, it is also one of the hardest rocks on the surface, second only to diamonds. It not only has high hardness, but is also more difficult to process than marble. It is also resistant to acid, weathering, and water erosion. It has a compressive strength of 15,000~20,000 psi. Under normal use, the appearance and color can be maintained. century. It is precisely because granite is so "stubborn" that people like to use it for exterior wall finishes, eaves pillars, wall foundations, floors, and steles, and it can often shine in some magnificent decoration projects.

So, why can granite be so hard? In fact, this is mainly for two reasons.

One is because of the composition of granite. We all know that the granite that we often use as processing building materials is mainly composed of feldspar (usually potassium feldspar and sodium anorthite) and quartz, with a small amount of mica (mainly biotite) mixed in. , It is also rich in trace minerals, such as zircon, apatite, magnetite, ilmenite and sphene. Among them, feldspar and quartz, the mineral particles that make up more than 90% of granite, are rich in silica, which is an atomic crystal with a spatial network structure, hard and insoluble, and chemically inactive. Because of this, feldspar and quartz have the reputation of "two King Kong brothers", so it is not difficult to understand why granite is particularly strong.

In addition, granite belongs to igneous rock, which is formed by magma jetting out of the earth's surface or intruding into the crust to cool and solidify. On the one hand, granite appears to have uniform particle size, inlaid and granular crystal structure. On the other hand, the mineral particles inside the granite are very closely connected, with very small gaps, and pores often do not account for the total volume of the rock. 1%. Therefore, granite is relatively more resistant to water erosion and more difficult to be processed.