Rock (geology)

Last updated

The Grand Canyon is an incision through layers of sedimentary rocks. Marsh Butte and Geikie Peak, Grand Canyon.jpg
The Grand Canyon is an incision through layers of sedimentary rocks.

In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects.


Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing rocks. Metamorphic rocks are formed when existing rocks are subjected to such high pressures and temperatures that they are transformed without significant melting.

Humanity has made use of rocks since the earliest humans. This early period, called the Stone Age, saw the development of many stone tools. Stone was then used as a major component in the construction of buildings and early infrastructure. Mining developed to extract rocks from the Earth and obtain the minerals within them, including metals. Modern technology has allowed the development of new man-made rocks and rock-like substances, such as concrete.


Geology is the study of Earth and its components, including the study of rock formations. Petrology is the study of the character and origin of rocks. Mineralogy is the study of the mineral components that create rocks. The study of rocks and their components has contributed to the geological understanding of Earth's history, the archaeological understanding of human history, and the development of engineering and technology in human society. [1]

While the history of geology includes many theories of rocks and their origins that have persisted throughout human history, the study of rocks was developed as a formal science during the 19th century. Plutonism was developed as a theory during this time, and the discovery of radioactive decay in 1896 allowed for the radiocarbon dating of rocks. Understanding of plate tectonics developed in the 20th century. [2]


A balancing rock called Kummakivi (literally "strange stone") Kummakivi balancing rock in Ruokolahti, Finland.jpg
A balancing rock called Kummakivi (literally "strange stone")

Rocks are composed primarily of grains of minerals, which are crystalline solids formed from atoms chemically bonded into an orderly structure. [4] :3 Some rocks also contain mineraloids, which are rigid, mineral-like substances, such as volcanic glass, [5] :55,79 that lacks crystalline structure. The types and abundance of minerals in a rock are determined by the manner in which it was formed.

Most rocks contain silicate minerals, compounds that include silica tetrahedra in their crystal lattice, and account for about one-third of all known mineral species and about 95% of the earth's crust. [6] The proportion of silica in rocks and minerals is a major factor in determining their names and properties. [7]

Rock outcrop along a mountain creek near Orosi, Costa Rica. DirkvdM rocks.jpg
Rock outcrop along a mountain creek near Orosí, Costa Rica.

Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. These physical properties are the result of the processes that formed the rocks. [5] Over the course of time, rocks can be transformed from one type into another, as described by a geological model called the rock cycle. This transformation produces three general classes of rock: igneous, sedimentary and metamorphic.

Those three classes are subdivided into many groups. There are, however, no hard-and-fast boundaries between allied rocks. By increase or decrease in the proportions of their minerals, they pass through gradations from one to the other; the distinctive structures of one kind of rock may thus be traced, gradually merging into those of another. Hence the definitions adopted in rock names simply correspond to selected points in a continuously graduated series. [8]

Igneous rock

Sample of igneous gabbro GabbroRockCreek1.jpg
Sample of igneous gabbro

Igneous rock (derived from the Latin word igneus, meaning of fire, from ignis meaning fire) [9] is formed through the cooling and solidification of magma or lava. This magma may be derived from partial melts of pre-existing rocks in either a planet's mantle or crust. Typically, the melting of rocks is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. [10] :591–599

Igneous rocks are divided into two main categories:

Magmas tend to become richer in silica as they rise towards the Earth's surface, a process called magma differentiation . This occurs both because minerals low in silica crystallize out of the magma as it begins to cool (Bowen's reaction series) and because the magma assimilates some of the crustal rock through which it ascends ( country rock ), and crustal rock tends to be high in silica. Silica content is thus the most important chemical criterion for classifying igneous rock. [7] The content of alkali metal oxides is next in importance. [11]

About 65% of the Earth's crust by volume consists of igneous rocks. Of these, 66% are basalt and gabbro, 16% are granite, and 17% granodiorite and diorite. Only 0.6% are syenite and 0.3% are ultramafic. The oceanic crust is 99% basalt, which is an igneous rock of mafic composition. Granite and similar rocks, known as granitoids, dominate the continental crust. [12] [13]

Sedimentary rock

Sedimentary sandstone with iron oxide bands "Liesegang banding" in quartzose sandstone (Upper Paleozoic; quarry near Crossville, Tennessee, USA) 2 (40280403530).jpg
Sedimentary sandstone with iron oxide bands

Sedimentary rocks are formed at the earth's surface by the accumulation and cementation of fragments of earlier rocks, minerals, and organisms [14] or as chemical precipitates and organic growths in water (sedimentation). This process causes clastic sediments (pieces of rock) or organic particles (detritus) to settle and accumulate or for minerals to chemically precipitate (evaporite) from a solution. The particulate matter then undergoes compaction and cementation at moderate temperatures and pressures (diagenesis). [5] :265–280 [15] :147–154

Before being deposited, sediments are formed by weathering of earlier rocks by erosion in a source area and then transported to the place of deposition by water, wind, ice, mass movement or glaciers (agents of denudation). [5] About 7.9% of the crust by volume is composed of sedimentary rocks, with 82% of those being shales, while the remainder consists of 6% limestone and 12% sandstone and arkoses. [13] Sedimentary rocks often contain fossils. Sedimentary rocks form under the influence of gravity and typically are deposited in horizontal or near horizontal layers or strata, and may be referred to as stratified rocks. [16]

Sediment and the particles of clastic sedimentary rocks can be further classified by grain size. The smallest sediments are clay, followed by silt, sand, and gravel. Some systems include cobbles and boulders as measurements. [17]

Metamorphic rock

Metamorphic banded gneiss Skagit-gneiss-Cascades.jpg
Metamorphic banded gneiss

Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism, meaning to "change in form". The result is a profound change in physical properties and chemistry of the stone. The original rock, known as the protolith, transforms into other mineral types or other forms of the same minerals, by recrystallization. [5] The temperatures and pressures required for this process are always higher than those found at the Earth's surface: temperatures greater than 150 to 200 °C and pressures greater than 1500 bars. [18] This occurs, for example, when continental plates collide. [19] :31–33,134–139 Metamorphic rocks compose 27.4% of the crust by volume. [13]

The three major classes of metamorphic rock are based upon the formation mechanism. An intrusion of magma that heats the surrounding rock causes contact metamorphism—a temperature-dominated transformation. Pressure metamorphism occurs when sediments are buried deep under the ground; pressure is dominant, and temperature plays a smaller role. This is termed burial metamorphism, and it can result in rocks such as jade. Where both heat and pressure play a role, the mechanism is termed regional metamorphism. This is typically found in mountain-building regions. [7]

Depending on the structure, metamorphic rocks are divided into two general categories. Those that possess a texture are referred to as foliated; the remainders are termed non-foliated. The name of the rock is then determined based on the types of minerals present. Schists are foliated rocks that are primarily composed of lamellar minerals such as micas. A gneiss has visible bands of differing lightness, with a common example being the granite gneiss. Other varieties of foliated rock include slates, phyllites, and mylonite. Familiar examples of non-foliated metamorphic rocks include marble, soapstone, and serpentine. This branch contains quartzite—a metamorphosed form of sandstone—and hornfels. [7]

Extraterrestrial rocks

Though most understanding of rocks comes from those of Earth, rocks make up many of the universe's celestial bodies. In the Solar System, Mars, Venus, and Mercury are composed of rock, as are many natural satellites, asteroids, and meteoroids. Meteorites that fall to Earth provide evidence of extraterrestrial rocks and their composition. They are typically heavier than rocks on Earth. Asteroid rocks can also be brought to Earth through space missions, such as the Hayabusa mission. [20] Lunar rocks and Martian rocks have also been studied. [21]

Human use

Ceremonial cairn of rocks, an ovoo, from Mongolia TallOvoo.JPG
Ceremonial cairn of rocks, an ovoo, from Mongolia

The use of rock has had a huge impact on the cultural and technological development of the human race. Rock has been used by humans and other hominids for at least 2.5 million years. [22] Lithic technology marks some of the oldest and continuously used technologies. The mining of rock for its metal content has been one of the most important factors of human advancement, and has progressed at different rates in different places, in part because of the kind of metals available from the rock of a region.

Anthropic rock

Anthropic rock is synthetic or restructured rock formed by human activity. Concrete is recognized as a man-made rock constituted of natural and processed rock and having been developed since Ancient Rome. [23] Rock can also be modified with other substances to develop new forms, such as epoxy granite. [24] Artificial stone has also been developed, such as Coade stone. [25] Geologist James R. Underwood has proposed anthropic rock as a fourth class of rocks alongside igneous, sedimentary, and metamorphic. [26]


A stonehouse on the hill in Sastamala, Finland Pirunvuoren kivilinna.jpg
A stonehouse on the hill in Sastamala, Finland
Raised garden bed with natural stones Hochbeet aus Naturstein.jpg
Raised garden bed with natural stones

Rock varies greatly in strength, from quartzites having a tensile strength in excess of 300 MPa [27] to sedimentary rock so soft it can be crumbled with bare fingers (that is, it is friable ). [28] (For comparison, structural steel has a tensile strength of around 350 MPa. [29] ) Relatively soft, easily worked sedimentary rock was quarried for construction as early as 4000 BCE in Egypt, [30] and stone was used to build fortifications in Inner Mongolia as early as 2800 BCE. [31] The soft rock, tuff, is common in Italy, and the Romans used it for many buildings and bridges. [32] Limestone was widely used in construction in the Middle Ages in Europe [33] and remained popular into the 20th century. [34]


Mi Vida uranium mine near Moab, Utah UraniumMineUtah.JPG
Mi Vida uranium mine near Moab, Utah

Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. [35] The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock salt, potash, construction aggregate and dimension stone. Mining is required to obtain any material that cannot be grown through agricultural processes, or created artificially in a laboratory or factory. Mining in a wider sense comprises extraction of any resource (e.g. petroleum, natural gas, salt or even water) from the earth. [36]

Mining of rock and metals has been done since prehistoric times. Modern mining processes involve prospecting for mineral deposits, analysis of the profit potential of a proposed mine, extraction of the desired materials, and finally reclamation of the land to prepare it for other uses once mining ceases. [37]

Mining processes may create negative impacts on the environment both during the mining operations and for years after mining has ceased. These potential impacts have led to most of the world's nations adopting regulations to manage negative effects of mining operations. [38]


Stone tools have been used for millions of years by humans and earlier hominids. The Stone Age was a period of widespread stone tool usage. [39] Early Stone Age tools were simple implements, such as hammerstones and sharp flakes. Middle Stone Age tools featured sharpened points to be used as projectile points, awls, or scrapers. Late Stone Age tools were developed with craftsmanship and distinct cultural identities. [40] Stone tools were largely superseded by copper and bronze tools following the development of metallurgy.

See also

Related Research Articles

Granite Common type of intrusive, felsic, igneous rock with granular structure

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 underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers.

Gneiss Common high-grade metamorphic rock

Gneiss is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures and pressures than schist. Gneiss nearly always shows a banded texture characterized by alternating darker and lighter colored bands and without a distinct cleavage.

Metamorphic rock Rock that was subjected to heat and pressure

Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than 150 to 200 °C and, often, elevated pressure of 100 megapascals (1,000 bar) or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock.

Rhyolite Igneous, volcanic rock, of felsic (silica-rich) composition

Rhyolite is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase. It is the extrusive equivalent to granite.

Metamorphism Change of minerals in pre-existing rocks without melting into liquid magma

Metamorphism is the transformation of existing rock to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of 150 to 200 °C, and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface.

Andesite Type of volcanic rock

Andesite is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende.

Migmatite Mixture of metamorphic rock and igneous rock

Migmatite is a composite rock found in medium and high-grade metamorphic environments. It consists of two or more constituents often layered repetitively; one layer was formerly paleosome, a metamorphic rock that was reconstituted subsequently by partial melting; the alternate layer has a pegmatitic, aplitic, granitic or generally plutonic appearance. Commonly, migmatites occur below deformed metamorphic rocks that represent the base of eroded mountain chains, commonly within Precambrian cratonic blocks,

Petrology Branch of geology that studies the formation, composition, distribution and structure of rocks

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 because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock.

Quartzite Hard, non-foliated metamorphic rock which was originally pure quartz sandstone

Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to grey, though quartzites often occur in various shades of pink and red due to varying amounts of hematite. Other colors, such as yellow, green, blue and orange, are due to other minerals.

Lithology Description of its physical characteristics of a rock unit

The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples, or with low magnification microscopy. Physical characteristics include colour, texture, grain size, and composition. Lithology may refer to either a detailed description of these characteristics, or a summary of the gross physical character of a rock. Examples of lithologies in the second sense include sandstone, slate, basalt, or limestone.

Formation of rocks Process of rock formations

Terrestrial rocks are formed by three main mechanisms:

Chlorite group Type of mineral

The chlorites are a group of phyllosilicate minerals common in low-grade metamorphic rocks and in altered igneous rocks. Greenschist, formed by metamorphism of basalt or other low-silica volcanic rock, typically contains significant amounts of chlorite.

Rock cycle Transitional concept of geologic time

The rock cycle is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous. Each rock type is altered when it is forced out of its equilibrium conditions. For example, an igneous rock such as basalt may break down and dissolve when exposed to the atmosphere, or melt as it is subducted under a continent. Due to the driving forces of the rock cycle, plate tectonics and the water cycle, rocks do not remain in equilibrium and change as they encounter new environments. The rock cycle explains how the three rock types are related to each other, and how processes change from one type to another over time. This cyclical aspect makes rock change a geologic cycle and, on planets containing life, a biogeochemical cycle.

Rock microstructure includes the texture and small-scale structures of a rock. The words texture and microstructure are interchangeable, with the latter preferred in modern geological literature. However, texture is still acceptable because it is a useful means of identifying the origin of rocks, how they formed, and their appearance.

Foliation (geology)

Foliation in geology refers to repetitive layering in metamorphic rocks. Each layer can be as thin as a sheet of paper, or over a meter in thickness. The word comes from the Latin folium, meaning "leaf", and refers to the sheet-like planar structure. It is caused by shearing forces, or differential pressure. The layers form parallel to the direction of the shear, or perpendicular to the direction of higher pressure. Nonfoliated metamorphic rocks are typically formed in the absence of significant differential pressure or shear. Foliation is common in rocks affected by the regional metamorphic compression typical of areas of mountain belt formation.

Fractional crystallization (geology) Process of rock formation

Fractional crystallization, or crystal fractionation, is one of the most important geochemical and physical processes operating within crust and mantle of a rocky planetary body, such as the Earth. It is important in the formation of igneous rocks because it is one of the main processes of magmatic differentiation. Fractional crystallization is also important in the formation of sedimentary evaporite rocks.

Igneous intrusion Body of intrusive igneous rocks

In geology, an igneous intrusion is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California.

This glossary of geology is a list of definitions of terms and concepts relevant to geology, its sub-disciplines, and related fields. For other terms related to the Earth sciences, see Glossary of geography terms.

Igneous rock Rock formed through the cooling and solidification of magma or lava

Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava.

Subduction zone metamorphism Changes of rock due to pressure and heat near a subduction zone

A subduction zone is a region of the earth's crust where one tectonic plate moves under another tectonic plate; oceanic crust gets recycled back into the mantle and continental crust gets created by the formation of arc magmas. Arc magmas account for more than 20% of terrestrially produced magmas and are produced by the dehydration of minerals within the subducting slab as it descends into the mantle and are accreted onto the base of the overriding continental plate. Subduction zones host a unique variety of rock types created by the high-pressure, low-temperature conditions a subducting slab encounters during its descent. The metamorphic conditions the slab passes through in this process creates and destroys water bearing (hydrous) mineral phases, releasing water into the mantle. This water lowers the melting point of mantle rock, initiating melting. Understanding the timing and conditions in which these dehydration reactions occur, is key to interpreting mantle melting, volcanic arc magmatism, and the formation of continental crust.


  1. Haldar, S. K. (2013). "Introduction". Introduction to Mineralogy and Petrology. Elsevier Science. pp. 1–37. ISBN   9780124167100.
  2. O'Hara, Kieran D. (2018). "The Structure of Geological Revolutions". A Brief History of Geology (1 ed.). Cambridge University Press. pp. 247–259. doi:10.1017/9781316809990.013. ISBN   978-1-316-80999-0.
  3. Kummakivi, Unusual
  4. Nesse, William D. (2000). Introduction to mineralogy. New York: Oxford University Press. ISBN   9780195106916.
  5. 1 2 3 4 5 6 Blatt, Harvey; Tracy, Robert J. (1996). Petrology (2nd ed.). W.H. Freeman. ISBN   978-0-7167-2438-4.
  6. Heinen, Wouter; Oehler, John H. (1979). "Evolutionary Aspects of Biological Involvement in the Cycling of Silica". In Trudinger, P.A.; Swaine, D.J. (eds.). Biogeochemical Cycling of Mineral-Forming Elements. Amsterdam: Elsevier. p. 431. ISBN   9780080874623 . Retrieved 13 April 2020.
  7. 1 2 3 4 Wilson, James Robert (1995), A collector's guide to rock, mineral & fossil localities of Utah, Utah Geological Survey, pp. 1–22, ISBN   978-1-55791-336-4, archived from the original on 19 November 2016.
  8. Wikisource-logo.svg One or more of the preceding sentences incorporates text from a publication now in the public domain :  Flett, John Smith (1911). "Petrology". In Chisholm, Hugh (ed.). Encyclopædia Britannica . Vol. 21 (11th ed.). Cambridge University Press. p. 327.
  9. ""igneous, adj."". OED Online. Oxford University Press. March 2021. Retrieved 17 April 2021.
  10. Philpotts, Anthony R.; Ague, Jay J. (2009). Principles of igneous and metamorphic petrology (2nd ed.). Cambridge, UK: Cambridge University Press. ISBN   9780521880060.
  11. Le Maitre, R. W.; Streckeisen, A.; Zanettin, B.; Le Bas, M. J.; Bonin, B.; Bateman, P.; Bellieni, G.; Dudek, A.; Efremova, S.; Keller, J.; Lamere, J.; Sabine, P. A.; Schmid, R.; Sorensen, H.; Woolley, A. R., eds. (2002). Igneous Rocks: A Classification and Glossary of Terms, Recommendations of the International Union of Geological Sciences, Subcommission of the Systematics of Igneous Rocks (2nd ed.). Cambridge University Press. ISBN   0-521-66215-X.
  12. Condie, Kent C. (2015). Plate Tectonics & Crustal Evolution (2nd ed.). New York: Pergamon. p. 68. ISBN   9781483100142 . Retrieved 13 April 2020.
  13. 1 2 3 Bucher, Kurt; Grapes, Rodney (2011), Petrogenesis of Metamorphic Rocks, Heidelberg: Springer, pp. 23–24, ISBN   978-3-540-74168-8, archived from the original on 19 November 2016.
  14. Gilluly, James (1959). Principles of Geology . W.H. Freeman.
  15. Boggs, Sam (2006). Principles of sedimentology and stratigraphy (4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall. ISBN   0131547283.
  16. Monroe, James S.; Wicander, Reed (2008). The Changing Earth: Exploring Geology and Evolution (5th ed.). Belmont, CA: Brooks/Cole. p. 438. ISBN   9780495554806 . Retrieved 13 April 2020.
  17. Blott, Simon J.; Pye, Kenneth (2012). "Particle size scales and classification of sediment types based on particle size distributions: Review and recommended procedures". Sedimentology. 59 (7): 2071–2096. Bibcode:2012Sedim..59.2071B. doi:10.1111/j.1365-3091.2012.01335.x. ISSN   0037-0746. S2CID   130084299.
  18. Blatt, Harvey and Robert J. Tracy, Petrology, W.H.Freeman, 2nd ed., 1996, p. 355 ISBN   0-7167-2438-3
  19. Lillie, Robert J. (2005). Parks and plates : the geology of our national parks, monuments, and seashores (1st ed.). New York: W.W. Norton. ISBN   0393924076.
  20. Kwok, Sun (2013). "Rocks and Dust in the Planetary Neighborhood". Stardust: The Cosmic Seeds of Life. Astronomers' Universe. Springer. pp. 11–23. doi:10.1007/978-3-642-32802-2_2. ISBN   9783642328022.
  21. Allen, Carlton; Allton, Judith; Lofgren, Gary; Righter, Kevin; Zolensky, Michael (2011). "Curating NASA's extraterrestrial samples—Past, present, and future". Geochemistry. 71 (1): 1–20. Bibcode:2011ChEG...71....1A. doi:10.1016/j.chemer.2010.12.003. hdl:2060/20100042395.
  22. William Haviland, Dana Walrath, Harald Prins, Bunny McBride, Evolution and Prehistory: The Human Challenge, p. 166
  23. Fookes, Peter G.; Walker, Mike J. (2010). "Concrete: a man-made rock?". Geology Today. 26 (2): 65–71. doi:10.1111/j.1365-2451.2010.00748.x. S2CID   129456840.
  24. McKeown, P.A.; Morgan, G.H. (1979). "Epoxy granite: a structural material for precision machines". Precision Engineering. 1 (4): 227–229. doi:10.1016/0141-6359(79)90104-1.
  25. Freestone, Ian (1 January 1991). "Forgotten but not lost: the secret of Coade Stone". Proceedings of the Geologists' Association. 102 (2): 135–138. doi:10.1016/S0016-7878(08)80072-7. ISSN   0016-7878.
  26. Underwood, James R. (1 February 2001). "Anthropic rocks as a fourth basic class". Environmental and Engineering Geoscience. 7 (1): 104–110. doi:10.2113/gseegeosci.7.1.104. ISSN   1078-7275.
  27. Amadei, B. "Strength properties of rocks and rock masses" (PDF). Civil, Environmental, and Architectural Engineering. University of Colorado Boulder. Retrieved 18 April 2021.
  28. Jackson, Julia A., ed. (1997). "Friable". Glossary of geology (Fourth ed.). Alexandria, Viriginia: American Geological Institute. ISBN   0922152349.
  29. Bjorhovde, Reidar (2004). "Development and use of high performance steel". Journal of Constructional Steel Research. 60 (3–5): 393–400. doi:10.1016/S0143-974X(03)00118-4.
  30. Klemm, Dietrich D.; Klemm, Rosemarie (2001). "The building stones of ancient Egypt – a gift of its geology". Journal of African Earth Sciences. 33 (3–4): 631–642. Bibcode:2001JAfES..33..631K. doi:10.1016/S0899-5362(01)00085-9.
  31. Shelach, Gideon; Raphael, Kate; Jaffe, Yitzhak (2011). "Sanzuodian: the structure, function and social significance of the earliest stone fortified sites in China". Antiquity. 85 (327): 11–26. doi:10.1017/S0003598X00067405. S2CID   163488276.
  32. Jackson, M. D.; Marra, F.; Hay, R. L.; Cawood, C.; Winkler, E. M. (2005). "The Judicious Selection and Preservation of Tuff and Travertine Building Stone in Ancient Rome*". Archaeometry. 47 (3): 485–510. doi:10.1111/j.1475-4754.2005.00215.x.
  33. Ashurst, John; Dimes, Francis G. (1998). Conservation of building and decorative stone. Butterworth-Heinemann. p. 117. ISBN   978-0-7506-3898-2.
  34. "Welcome to the Limestone City". Archived from the original on 20 February 2008. Retrieved 13 February 2008.
  35. Gajul, Shekhar (28 July 2018). "Underground Mining Equipment Market 2017 Global Key Players, Share, Challenges, Industry Size, Growth Opportunities & Forecast To 2021". Journalist Book. Archived from the original on 28 July 2018. Retrieved 28 July 2018.
  36. Botin, J.A., ed. (2009). Sustainable Management of Mining Operations. Denver, CO: Society for Mining, Metallurgy, and Exploration. ISBN   978-0-87335-267-3.
  37. Wilson, Arthur (1996). The Living Rock: The Story of Metals Since Earliest Times and Their Impact on Developing Civilization. Cambridge, England: Woodhead Publishing. ISBN   978-1-85573-301-5.
  38. Terrascope. "Environmental Risks of Mining". The Future of strategic Natural Resources. Cambridge, Massachusetts: Massachusetts Institute of Technology. Archived from the original on 20 September 2014. Retrieved 10 September 2014.
  39. "Oldest tool use and meat-eating revealed | Natural History Museum". 18 August 2010. Archived from the original on 18 August 2010.
  40. "Stone Tools". The Smithsonian Institution's Human Origins Program. Smithsonian Institution. 29 June 2022. Retrieved 9 August 2022.