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Aggregate (geology)

earth science Maturity 7-9 Next article →

An aggregate is a group of small parts. It is a mass made of many pieces. The word has three meanings in Earth science.

Lapislazuli from Afghanistan other view
Lapislazuli from Afghanistan other view

One meaning is for minerals and rocks. Another meaning is for soil. The third meaning is for building things. This word helps scientists talk about how things are grouped together.

In mineralogy, an aggregate is a mass of crystals. It can also be made of mineraloid or rock particles. One way it works is by grouping crystals together. For example, dolomite is an aggregate of dolomite crystals. Rock gypsum is an aggregate of gypsum crystals.

Lapislazuli from Afghanistan other view
Lapislazuli from Afghanistan other view

Lapis lazuli is a very special rock. It is an aggregate of many different minerals. These include lazurite, pyrite, and phlogopite. It also has calcite, potassium feldspar, wollastonite, and sodalite group minerals.

Soil science uses the word in a different way. Here, an aggregate is a mass of soil particles. These groups can form on their own in nature. Scientists call these natural groups peds. Sometimes, people make soil masses by hand. These man-made groups are called clods.

Subangular Blocky Soil Aggregate in Spain
Subangular Blocky Soil Aggregate in Spain

Understanding these shapes helps us learn about the ground.

Builders use a type called construction aggregate. This is sand, gravel, or crushed rock. These materials are mined or quarried from the Earth.

Kiesabbau Forstenrieder Park
Kiesabbau Forstenrieder Park

They are used as a building material. People make about 6 billion tons of concrete every year. This concrete uses a lot of aggregate. Common types include basalt, dolomite, granite, gravel, limestone, and sandstone.

You can see aggregates in many places. They are in the stones you find. They are in the soil in a garden. They are even in the sidewalks you walk on.

Kiesabbau Forstenrieder Park
Kiesabbau Forstenrieder Park

Many things around you are made of these small parts. From huge buildings to tiny soil bits, aggregates are everywhere. They help hold the world together.

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🖼️ Images & Media (3)
File:Lapislazuli from Afghanistan other view.jpg
Lapislazuli from Afghanistan other view.jpg
File:Kiesabbau Forstenrieder Park.jpg
Kiesabbau Forstenrieder Park.jpg
File:Subangular Blocky Soil Aggregate in Spain.jpg
Subangular Blocky Soil Aggregate in Spain.jpg
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