Aggregate (geology)


In the Earth sciences, aggregate has three possible meanings.
In mineralogy and petrology, an aggregate is a mass of mineral crystals, mineraloid particles or rock particles. Examples are dolomite, which is an aggregate of crystals of the mineral dolomite, and rock gypsum, which is an aggregate of crystals of the mineral gypsum. Lapis lazuli, for another example, is a type of rock composed of an aggregate of crystals of many minerals including lazurite, pyrite, phlogopite, calcite, potassium feldspar, wollastonite and some sodalite group minerals.
In pedology, an aggregate is a mass of soil particles. If it has formed naturally, it can be called a ped; if formed artificially, it can be called a clod.
In the construction industry, in contrast to the Earth sciences, an aggregate is sand, gravel or crushed rock that has been mined or quarried for use as a building material.

Construction aggregate examples

Aggregates are used extensively in the construction industry. Often in making concrete, a construction aggregate is used,
with about 6 billion tons of concrete produced per year.