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 (often referred to as construction aggregate) is sand, gravel or crushed rock that has been mined or quarried for use as a building material.
Construction aggregate examples
basalt
dolomite granite gravel limestoneSame Day Aggregates: Types of Aggregates - Same Day Aggregates , accessdate: March 25, 2017Indiana Mineral Aggregates Association | Carmel, IN: What are aggregates? - Indiana Mineral Aggregates Association | Carmel, IN, accessdate: March 25, 2017 sand sandstone
Use in industry
Aggregates are used extensively in the construction industry.Introduction (1): What are Aggregates? « Herefordshire & Worcestershire Earth Heritage Trust: Introduction (1): What are Aggregates? « Herefordshire & Worcestershire Earth Heritage Trust , accessdate: March 23, 2017Define Aggregate at Dictionary.com: aggregate, accessdate: March 23, 2017 Often in making concrete, a construction aggregate is used, with about 6 billion tons of concrete produced per year.
See also Interfacial Transition Zone (ITZ) Soil structure
References
External links What are aggregates? Concrete Aggregates — Geological Considerations What is aggregate? — The Bare Essentials of Concrete — Part 2 YouTube video (duration 4 minutes)