In the
Earth science
Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical, chemical, and biological complex constitutions and synergistic linkages of Earth's four sphere ...
s, aggregate has three possible meanings.
In
mineralogy
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the proce ...
and
petrology
Petrology () is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together ...
, an aggregate is a mass of
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...
crystals,
mineraloid
A mineraloid is a naturally occurring mineral-like substance that does not demonstrate crystallinity. Mineraloids possess chemical compositions that vary beyond the generally accepted ranges for specific minerals. For example, obsidian is an a ...
particles or
rock particles.
Examples are
dolomite Dolomite may refer to:
*Dolomite (mineral), a carbonate mineral
*Dolomite (rock), also known as dolostone, a sedimentary carbonate rock
*Dolomite, Alabama, United States, an unincorporated community
*Dolomite, California, United States, an unincor ...
, which is an aggregate of crystals of the mineral
dolomite Dolomite may refer to:
*Dolomite (mineral), a carbonate mineral
*Dolomite (rock), also known as dolostone, a sedimentary carbonate rock
*Dolomite, Alabama, United States, an unincorporated community
*Dolomite, California, United States, an unincor ...
,
and ''rock gypsum'', an aggregate of crystals of the mineral
gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywa ...
.
Lapis lazuli is a type of rock composed of an aggregate of crystals of many minerals including
lazurite
Lazurite is a tectosilicate mineral with sulfate, sulfur and chloride with formula . It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well‐formed crystals are rare. It is usual ...
,
pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic Luster (mineralogy), lust ...
,
phlogopite,
calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratc ...
,
potassium feldspar,
wollastonite and some
sodalite group minerals.
In the
construction
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and ...
industry, an aggregate (often referred to as a
construction aggregate
Construction aggregate, or simply aggregate, is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregate ...
) is
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...
,
gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
or crushed rock that has been
mined or
quarried
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environ ...
for use as a
building material
Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man- ...
.
In
pedology, an aggregate is a mass of soil particles. If the aggregate has formed naturally, it can be called a
ped
Peds are aggregates of soil particles formed as a result of pedogenic processes; this natural organization of particles forms discrete units separated by pores or voids. The term is generally used for macroscopic (visible; i.e. greater than 1 mm in ...
; if formed artificially, it can be called a clod.
Construction aggregate examples
*
basalt
Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...
*
dolomite Dolomite may refer to:
*Dolomite (mineral), a carbonate mineral
*Dolomite (rock), also known as dolostone, a sedimentary carbonate rock
*Dolomite, Alabama, United States, an unincorporated community
*Dolomite, California, United States, an unincor ...
*
granite
Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies un ...
*
gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone.
Gravel is classifi ...
*
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms w ...
[Same Day Aggregates]
Types of Aggregates - Same Day Aggregates
accessdate: March 25, 2017[Indiana Mineral Aggregates Association , Carmel, IN]
What are aggregates? - Indiana Mineral Aggregates Association , Carmel, IN
accessdate: March 25, 2017
*
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...
*
sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicat ...
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, 2017[Define Aggregate at Dictionary.com]
aggregate
accessdate: March 23, 2017 Often in making
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...
, a construction aggregate is used,
with about 6 billion tons of
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...
produced per year.
See also
*
Interfacial Transition Zone (ITZ)
*
Soil structure
References
External links
What are aggregates?
What is aggregate? — The Bare Essentials of Concrete — Part 2YouTube video (duration 4 minutes)
Industrial minerals
Mineralogy
Pedology
Petrology concepts
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