Granite mountain massive

Macro close-up of granite reveals feldspar, quartz and mica crystals, main components of this igneous rock that forms mountains like Mount Rushmore.

About this subject

Granite is a plutonic igneous rock, formed by the slow cooling of magma deep underground. Its phaneritic texture, with visible crystals, results from this process. The main minerals are feldspar (usually orthoclase or plagioclase), quartz, and mica (biotite or muscovite). The proportion of these minerals determines the color and type of granite, ranging from light gray to pink or red.

Granite mountains are common in ancient mountain ranges, such as the Serra do Mar in Brazil and the Andes. In Brazil, the Granito da Pedra do Baú in São Paulo is an example of a monumental granite formation. Granite is widely used in construction, for countertops, flooring, and cladding, due to its hardness and wear resistance. Historically, it was used in monuments like the Egyptian obelisk and the Rosetta Stone.

A curiosity: granite is the most abundant rock in the continental crust, and its formation can take millions of years. The presence of potassium feldspar gives granite its characteristic color. In macro close-ups, well-formed crystals are visible, highlighting the igneous texture. This rock is also used in sculptures and for producing crushed stone for concrete. Its low porosity makes it ideal for slopes and dams.

Frequently Asked Questions

What is the composition of granite?

Granite is mainly composed of feldspar, quartz, and mica. The proportion varies, but typically contains 20-60% feldspar, 20-50% quartz, and up to 10% mica.

Where are granite formations found?

Granite formations are common in ancient mountain ranges, such as the Serra do Mar (Brazil), the Alps, and the Andes. Notable examples include Mount Rushmore and Pedra do Baú.

What is granite used for?

Granite is used in construction (countertops, flooring, cladding), monuments, sculptures, and as crushed stone for concrete. Its durability and aesthetics make it popular.