Rocks are bound to be found wherever you go in this world. Without rocks, our home would be a drastically different place on Earth. Rocks are our solid foundation.
However, not all rocks are the same. In reality, each rock type has its distinctive qualities and characteristics, and there are hundreds of them.
It is feasible to impress your pals with your rocky knowledge, however it is not feasible to name every single rock on Earth.
We’ll give you a overview of 30 different types of rocks that you should be familiar with in this article. Here are some of the most spectacular types of rocks on the earth that you shouldn’t mistake for granite, from gleaming obsidian to stunning lapis lazuli.
30 Types of Rocks Common on Earth
Here’s your ultimate list of the 30 coolest types of rocks on Earth, from andesite to quartzite and everything in between:
Anorthosite is one of the Earth’s most fascinating rocks, made almost entirely out of plagioclase feldspar. What makes it so intriguing, though, is completely alien. In reality, one of the Moon’s first crustal materials is anorthosite!
Yep, anorthosite may be found in enormous amounts on the Moon, in addition to making up the majority of the High Peaks region in upstate New York’s Adirondack Mountains and various sections of Canada’s Shield.
The fact that geologists are still divided about how anorthosite forms is fascinating. Of course, anorthosite forms with such high concentrations of plagioclase feldspar, but it’s unclear why.
Obsidian is a jet-black and smooth rock with a long history in human culture. It is one of the most visually appealing types of rock.
Obsidian is a form of extrusive igneous rock that forms when felsic lavas from a volcano cool quickly once they are exposed to the atmosphere. It is also known as volcanic glass. The lava has little time to form crystals as a result of this fast cooling, and obsidian has a smooth texture as a consequence.
Obsidian is a kind of extrusive igneous rock that forms when felsic lavas from a volcano cool quickly once they are exposed to the atmosphere. It is also known as volcanic glass. The lava has little time to grow crystals as a consequence of this fast cooling, hence obsidian has a smooth surface.
Dolomite is one of the most well-known rock types in the Italian Alps, named after French geologist Déodat Gratet de Dolomieu. Dolomite, or dolostone, is a sedimentary rock that mostly consists of the mineral dolomite and is found extensively throughout the mountain range that bears its name (the Dolomites).
Dolomite and limestone are both formed from the collection and compaction of calcium carbonate in warm, shallow ocean basins, and they have many similarities. Dolomite is thought to occur when calcite reacts with magnesium-rich groundwater, according to some theories.
Dolomite is most well-known for its dolomite-rich Alps, which turn spectacular colors at sunrise and sunset, no matter which way you look at it. The Ladin language, which is spoken by the Ladin people, an ethnic group of the Dolomites, has a word for this phenomenon called enrosadira. The Dolomites become a must-see at sunset as a consequence of this occurrence, which turns them pink and violet.
Basalt is arguably the most widespread rock type on Earth. It’s a beautiful dark-colored fine-grained igneous rock. Basalt is created extrusively from lava flows above the Earth’s surface and is largely made up of pyroxene and plagioclase.
Because it underlies the majority of Earth’s ocean basins, basalt is quite plentiful. Basalt makes up the bulk of oceanic plates, and they are actively produced at divergent oceanic boundaries and at oceanic hotspots. It is not as prevalent on continental plates, but it does exist.
Basalt, on the other hand, is a highly plentiful rock on the Moon’s surface. Basalt, especially around Olympus Mons, the planet’s major shield volcano, may also be found on Mars.
Granite is more than a decorative rock, despite the fact that it has gained popularity in recent years as a high-end kitchen countertop. Granite, on the other hand, is an intrusive igneous rock with enormous feldspar and quartz crystals. Granites may also include micas and amphiboles, which give them additional color and character.
Because it is so common, granite is arguably the most well-known igneous rock on Earth. Granite is a durable rock with attractive topographic features, which attracts rock climbers in particular. Many of Yosemite Valley’s notable features, such as El Capitan, are made entirely of granite.
Granite is most likely the most widespread rock form in continental crust, whereas basalt is the most prevalent form of rock in oceanic crust. As a result of magma that cools beneath the Earth’s surface, it commonly forms in enormous batholiths or shields.
Tuff is a geological oddity, as it is made of consolidated volcanic ash. Some scientists consider it to be an igneous rock because it is made up of volcanic ash. Tuff, on the other hand, might be classified as a sedimentary rock if it is made up of consolidated sediments.
Tuff has long been a popular rock for construction, regardless of how you classify it. The moai, which are the island’s famed human-like sculptures, were made by the people of Rapa Nui (Easter Island) in this way.
It’s also worth noting that tuff comes in a variety of shapes and sizes, depending on the type of volcanoes from which they originate. In New Zealand, rhyolite tufts are frequent, whereas basaltic tufts are more prevalent in Scotland, Iceland, and the Faroe Islands.
Gneiss is a kind of foliated metamorphic rock that typically forms near the margins of convergent plate boundaries. It is famed for its exquisite folded bands. One of the reasons why gneiss has such distinct mineral bands is that it undergoes high-grade regional metamorphism during its formation.
Gneiss is made up of several different layers of rock. Shale, which may change into slate, then phyllite and schist before becoming gneiss, is one of the most common rock types.
Gneiss is made up of a variety of underlying rocks. Shale, phyllite, and schist may all be converted into gneiss before becoming rock types.
Gneiss is interesting in that its specific mineral composition is not specified, unlike many other types of rock. Gneiss is characterized by its bands, which show how the rock developed, and contains quartz and feldspar.
Pumice is an extrusive igneous rock with large gas bubbles that is deceivingly lightweight.
When lava cools after being expelled from a volcano, it forms. It has a considerable water and gas contents. Pumice stones are often significantly lighter in weight than you’d expect when the lava cools, producing tiny gas bubbles.
Because pumice has a high silica content, the majority of it is lightly colored. Because it is a common material in construction, it is mined heavily all around the globe. Pumice is also employed in the production of rubber erasers and absorbent materials like cat litter, among other things.
Pumice stones, which are used for personal hygiene, may also be purchased. Because of its abrasive qualities, pumice has long been utilized to scrape off calluses from the skin.
Breccia (pronounced bre-CHE-a) is a funky sort of sedimentary rock that’s made up of glued fragments of other rocks compressed together.
It’s essentially an amalgamation of other rocks, which is similar to conglomerate. Yet, since a conglomerate must be made up of spherical rocks, while breccia is made up of angular rocks, they are not the same.
While breccia is classed as a sedimentary rock, it can be metamorphic, igneous, or sedimentary in origin. It has been utilized by humans for thousands of years in the form of building columns, and it has been used for aesthetic reasons.
Anthracite is the highest quality coal on the planet, and it is more commonly known as “coal.” It’s a highly condensed form of coal that has been substantially transformed and includes up to 98 percent carbon.
Anthracite has the greatest energy density of any other coal type, including bituminous, subbituminous, and lignite coal, because it contains such a significant amount of carbon. As a result, it has been used to generate electricity in the past.
The burning of anthracite, like that of all fossil fuels, has a negative impact on the environment. Coal dust inhalation over time may cause coal workers’ pneumoconiosis (black lung), which can have serious health implications for individuals who labor in coal mines.
Schist is a fascinating metamorphic rock that boasts enormous crystals and is well-known for its tendency to include huge garnets.
At convergent plate boundaries, schist is common. It’s made out of sedimentary rocks, such as shales and mudstones, that have undergone mid-grade metamorphism. As a result, mica, hornblende, quartz, and feldspar are frequently present in high concentrations.
The fact that schist can’t include huge garnet gems is perhaps the most well-known feature. The most abundant color for these magnificent stones is red, however almost any color is available. They’re huge, and their rich colors have made them popular as gemstones for a long time.
12. Lapis Lazuli
Lapis lazuli is a metamorphic rock with a deep blue coloration that is perhaps the most alluring on our list. Because of its beautiful hues, it has been regarded a semi-precious stone for thousands of years, and it has been regarded valuable to humans.
Lapis lazuli is often encountered through contact metamorphism around igneous intrusions. It’s mostly found in Afghanistan, although there are many other places around the globe where lapis lazuli is produced in reasonably significant amounts.
Lapis lazuli is often utilized to make pendants and earrings despite the fact that it is too delicate to be utilized in rings. In order to be gemstone quality, it needs to be extremely polished, but its gorgeous blue hues are impossible to ignore.
Llanite is a kind of magnificent extrusive igneous rock that is one of the world’s rarest. Although llanite is only found in one location in Llano County, Texas, it can be classified as a kind of rhyolite.
The combination of very distinctive blue quartz crystals and perthitic feldspar makes llanite special. On its own, blue quartz is uncommon, and it provides an aesthetic allure that no other mineral can match.
Suevite is a distinctive rock that’s sometimes known as an “impactite.” Impactites are any rock that occurs as a consequence of a meteor strike.
Suevite is thought to develop when nearby rock is heated to extremely high temperatures as a consequence of the pressure of an impact event, and then cooled very fast. Although little is known about it, it’s assumed that it happens. Various glasses and other crystals are formed as a result of this fast melting and cooling.
Suevite is made up of angular shards of these crystals and glasses, which makes it unique. It’s often utilized as a “diagnostic rock” by geologists to identify genuine impact craters.
Andesite is an extrusive igneous rock that’s often regarded as an intermediary between darkly colored basalts and mildly colored rhyolites. It’s another very common kind of rock.
The Andes mountains in South America are one of the world’s longest mountain ranges, and Andesite gets its name from them. Because it is produced by fast cooling andesitic lavas generated by volcanoes in the area, the rock is plentiful in the area.
In addition, at convergent plate boundaries, andesite is common, particularly when oceanic crust subducts beneath continental crust. Two meteorites that landed in Antarctica’s Graves Nunataks area have also been discovered.
Unakite is a kind of gemstone with beautiful green and pink hues that ranks second on our list. Its stunning pistachio-green epidote and pink orthoclase minerals are best displayed by a coarse-grained rock that undergoes metamorphosis.
In jewelry, sculpting, and building, Unakite is a favored material. Since it is reasonably priced, it is often employed. Nevertheless, it is simple to work with and brings outstanding colors to any building. In reality, unakite may be found on the front porch of the Smithsonian National Museum of Natural History in Washington, D.C.
The Unaka Mountains, which run parallel to the Blue Ridge Mountains in southern United States, are where the term unakite comes from. They are a subrange of the Blue Ridge Mountains that runs between Tennessee and North Carolina.
Amphibolite is a kind of metamorphic rock that occurs along convergent plate boundaries and is unusual in its properties. The amphibole, one of the minerals it’s named after, is the main mineral. Green is arguably the most well-known color of amphibole, which comes in a wide range of colors.
Plagioclase feldspar and hornblende are two other significant amphibolite minerals. Yet, one of the reasons it is so black is because it contains little, if any, quartz.
Humans have used amphibolite for centuries to make tools. In actuality, it has been discovered in Neolithic adzes, which are a kind of cutting instrument. Because of its great hardness and aesthetic, it’s also a fairly common stone used in paving and construction.
Caliche is a fascinating kind of sedimentary rock that’s sometimes referred to as calcrete or kankar. Calcium carbonate, sands, silts, gravels, and clays make up the majority of it. It’s essentially a natural cement.
Caliche is typically light in color, however there are certain darker variants out there as well. It may be found in the Mojave Desert in arid or semi-arid places all over the globe.
Caliche is particularly difficult to dig through, which makes it unique. While many sedimentary rocks aren’t particularly difficult to fracture, caliche’s natural cement may make it difficult during building projects. Caliche is also moderately impermeable, hence it may cause problems for farmers if it allows water to seep into the soil.
Coquina is a sedimentary rock that has distinctive aesthetic qualities and is a truly exceptional kind of limestone.
Coquina is distinguished by the fact that it is mostly, if not entirely, made up of trilobite, invertebrate, and mollusk shells. In reality, coquina is a Spanish term that refers to a sort of mollusk known as a “cockle.”
These rocks develop in shallow waters due to the accumulation of different shells, as one might anticipate. Coquina has a rough, yet captivating, texture that has made it popular for use in building in some coastal areas as a result of its composition.
The many bubble-like air holes in Scoria make it a type of igneous rock. If it’s formed from andesitic lava, it’s virtually usually dark in color, although it can be a little lighter.
When lava is ejected from a volcano during an eruption, this kind of rock develops. It contains large volumes of dissolved gasses. The scoria generates tiny air bubbles as a consequence of these dissolved gasses.
Cinder cones, which are a type of volcano, are most familiar with scoria. It’s worth noting, however, that scoria is typically created from basaltic lavas while pumice comes from rhyolitic lavas.
Marble is a metamorphic rock prized for its aesthetic qualities, and it is one of the most popular building and sculpting materials.
Metamorphism of limestones or dolostones produces marble. The carbonate crystals in limestone and dolostone rocks are recrystallized into an interlocking mosaic as a result of this metamorphism.
Most marbles have veins and swirls, even though pure marble is technically white. Impurities, such as chert, sand, silt, or iron oxides, cause the veins and swirls in this image. Certain marbles, which are the consequence of serpentines, also have green hues that you may notice.
Skarn is a metamorphic rock that forms near the margins of big magma bodies and is one of the lesser-known rocks on this list.
It develops via a specific manner known as metasomatism, which is when rocks are metamorphosed by mixing with hot, chemically active fluids. Carbonate rocks, such as marbles, dolomites, and limestones, account for the majority of skarns.
Large garnets, as well as other stones like sapphires and rubies, are frequently found in skarns. Lead, tin, copper, zinc, tungsten, molybdenum, and occasionally gold may be found in skarns.
Humans have utilized chert as a tool or building material since the beginning of time, and it has been used as such. Quartz makes up the majority of it, and petrification of wood can also produce it.
Cherts come in practically every color imaginable, and they are white or black in hue. The trace elements present in the rock itself typically give chert its color, although reddish cherts with minor amounts of oxidized iron are occasionally seen.
Chert has been employed as a material to make arrowheads and other equipment for millennia, much as obsidian has. Flint is a type of chert that has been utilized to make tools for millennia.
Humans have mined soapstone for millennia for both ornamental and practical purposes, making it another extremely useful rock.
A metamorphic rock that is primarily made up of talc is referred to as soapstone. Amphiboles, carbonates, chlorites, and pyroxenes may be found in it, as well as micas; nevertheless, soapstone must have talc to be categorized as soapstone.
Soapstone is non-absorbent and carveable, which makes it a popular choice. Humans have mined soapstone in every corner of the globe, including Ancient Egypt and India. It can also be found on the statue of Christ the Redeemer in Rio de Janeiro’s upper reaches.
Mariposite is a rock that may be identified as a mineral by certain geologists. A group of metamorphic rocks with huge concentrations of green micas is referred to as mariposite in informal terms.
Naturally, the green micas impart a distinct hue to these rocks, making them a remarkable building material.
Mariposite is derived from the California town of Mariposa. Several miners found that mariposite rocks frequently contained significant quantities of gold, which made it a prized sight during the California Gold Rush. The rock, however, may be found all over the world, including in Washington State in the US and on Newfoundland Island in Canada.
26. Oil Shale
Oil shale is a hydrocarbon-rich sedimentary rock that, as its name implies, contains a lot of liquid hydrocarbons. (Oil is used in cooking) Oil shale deposits may be found globally, particularly in the western United States, Australia, Brazil, and other regions of Europe.
Oil shale is a valuable resource in the fossil fuel sector because it can produce oil, as you may imagine. Extracting oil from oil shales, not to mention the environmental damage of burning oil, is typically quite costly.
Oil shale mining has negative environmental consequences in addition to its detrimental effects. It is known to release large amounts of water pollution in areas where it is mined, most notably because it releases substantial levels of heavy metals like mercury into surface water.
Gabbro is a darkly colored kind of intrusive igneous rock that may be found in batholiths along mid-ocean ridges and in ancient mountain ranges.
It develops when magma is cooled over a long period of time, allowing it to create massive crystals because of its rich iron and magnesium content. If you examine each rock’s basic chemical makeup, gabbro is the intrusive equivalent of basalt.
Gabbro is a name derived from a community in Tuscany, Italy. It was first discovered in the Italian Apennines in the eighteenth century, but it is now found across the globe, notably on Scotland’s famed Black Cuillin range on Skye.
The fossilized skeletons of diatoms, a type of microalgae, are used to make diatomite. Poland, Germany, the United States, Denmark, and Scotland are among the countries where it may be found.
The fossilized remains of diatoms, which are a type of microalgae, are used to make diatomite. Poland, Germany, the United States, Denmark, and Scotland are among the countries where it may be found.
Diatomite has been a common compound utilized to make air filters and abrasives for thousands of years, but it is now a trendy compound. Alfred Nobel used it to make his ground-breaking dynamite (okay, this time we really mean it—no more rock puns!) by stabilizing nitroglycerin.
Quartzite is a metamorphic rock that is practically essentially made of quartz and is therefore a very typical rock type.
When sandstones with a lot of quartz minerals are metamorphosed by heat and pressure, it is common. The grains of the sandstone recrystallize as a result of this metamorphism, giving the quartzite superhero strength.
Since quartzite is so hard and strong, it’s becoming a popular choice for everything from countertops to building. In many ways, it performs better than granite or marble, and it is significantly less costly than both. Quartzite countertops are also available, which are even more durable.
Hornfels, which is the term for a collection of rocks generated by contact metamorphism, is last but not least. As a result, they develop when the crystals in the original rock are re-aligned as a consequence of exposure to high heat.
Sedimentary rocks, such as limestone, sandstone, and shale are commonly used to create hornfels. Hornfels, on the other hand, is very hard and durable.
Because of its durability, hornfels was traditionally used in England to produce whetstones. Nevertheless, most current natural whetstones are made of quartz, just as novaculite is.
How Are Rocks Classified?
Let’s now talk about how rocks are classified, since you’re familiar with 30 amazing types of rock.
Several rock types, such as igneous, metamorphic, and sedimentary, have been discussed throughout this article. Because they group rocks based on their origin, these three rock types are considered to be the most common.
The idea is that there are three primary ways that rocks form, despite the fact that there is enough information about their classification to fill many books.
When magma or lava cool, they form igneous rocks. Intrusive magma heats in the Earth’s crust, whereas extrusive magma cools on the surface or in the seafloor. They may be intrusive or extrusive, depending on how they are formed. Basalt and granite are examples of non-metallic materials.
When an existing rock is subjected to extremely high temperatures or pressures, metamorphic rocks develop. Igneous, sedimentary, or even metamorphic rocks may be found in the original rock. Schist and gneiss are examples of rocks.
The accretion and compression of minerals or organic materials create sedimentary rocks. Shallow seas are the most common environment for this, but it can happen in any environment. Sandstones and breccias are examples of this.
The Rock Cycle
Over time, each of the three main types of rock we discussed (igneous, sedimentary, and metamorphic) goes through changes.
Sedimentary rocks, for example, may be formed Millions of years later after an igneous rock has eroded into sediments. Eventually, metamorphic rocks develop when the same sedimentary rock is subjected to high temperatures and pressures.
The rock cycle encompasses all of the rocks on Earth in this manner. The rock cycle, like the water cycle, is a natural process that takes place over geologic time. Plate tectonics and erosion are two forces that influence the rock cycle.
The rock cycle acts as a recycling mechanism for rocks, according to the central concept. All of the rocks on Earth have existed since the planet formed, except for those that arrived via meteor (of course). The Law of Conservation of Mass states that matter cannot be created or destroyed.
As a result, during their lifetimes, the rocks you see on our planet today have most likely changed many times. These could have evolved from igneous rocks to metamorphic rocks, through the rest of their evolution being eroded and compacted into sedimentary rocks before being subducted and melted.
The rock cycle reminds us that geologic time is now and that the world around us is constantly changing, even if it takes a very, very long time for this to happen.
Types of Rocks FAQs
To some of your most commonly asked rock questions, here are our answers:
What Are The 3 Rock Types?
Igneous, sedimentary, and metamorphic rock are the three fundamental rock types. Sedimentary rocks are compacted groupings of sediment, such as sand or mud, and develop through the cooling of magma or lava. Lastly, any rock that has been subjected to high temperatures and/or pressure is referred to as metamorphic.
Is A Mineral Considered A Rock?
There is a distinction between minerals and rocks. A mineral has a unique chemical structure and is an inorganic compound. Rocks are composed of minerals and other substances, and they are solid masses. Multiple minerals or just one may be found in a rock. Mono-mineralic rocks are those that have just one mineral.