As an Amazon Associate, I earn from qualifying purchases with no additional costs for you.
Igneous rocks are an integral part of all rocks that make up our planet; that is why there are a lot of interesting facts to be shared. Igneous rocks are one of three members of rock types. Igneous rocks are initially crystallized from magma or lava.
Igneous rocks have unique chemical and mineral compositions. They can be a source of rare elements of almost imperceptible concentrations and make huge breathtaking landscapes. They are formations, which can tell the age of mountain ranges formation and which can serve you as a kitchen tabletop.
Diamonds are mined from igneous rocks called kimberlites. Igneous rocks are a source of precious and base metals, rare earth elements, and gemstones. We would like to share some interesting, fun, and scientific facts about igneous rocks, which will not leave anyone indifferent.
If you are interested in checking out the best books about rocks and minerals identification you can find them by clickinghere(Amazon link).
Interesting Fact: Diamonds are extracted from igneous rocks.
Kimberlites are extrusive igneous rock (e.g., a volcanic rock) that transport diamonds from 150-700 km depths in a rare volcanic eruption of a kimberlite magma. Luckily, since diamond is the hardest mineral, it can usually survive such rough handling. Kimberlite may occur in the field as dikes or pipes.
Kimberlite is the name given to a silica-poor and magnesium-rich extrusive igneous rock (e.g., a volcanic rock) that contains major amounts of olivine, often serpentinized. It is a highly variable mixture of melt, minerals crystallizing from the melt, and foreign crystals and rock pieces.
On their turbulent journey upwards, magmas assimilate other types of minerals, collectively referred to as xenoliths (Greek for “foreign rocks”). The xenoliths found in kimberlite include diamonds. The vast majority of the diamonds mined in the world today are found in kimberlite rocks.
Cool Fact: Geodes are formed in igneous rocks.
Geodes – a spherical geological formation, with a hollow inside lined with crystals, are usually found in volcanic igneous rocks with andesitic and dacitic composition mostly. The inner part of the geode reveals perfectly formed crystals of rock quartz and amethyst growing towards the center of the hollow.
Voids, which will be a geode in the future, are formed during magma uplift from beneath the earth to the surface. Some gas bubbles had not enough time to escape from the lava flow and solidified inside, providing a space for crystal growth.
Groundwater or low-temperature hydrothermal solutions precipitate in voids forming crystals growing towards the center of the void. The most common crystals found inside a geode are quartz and its purple variety amethyst.
TIP: Geodes are one the most popular rocks among rockhounds. Geodes can be quite valuable. Find out the real value of geodes in the article below:
The Value of Geodes: Are They Worth Anything?
Fun Fact: Igneous rocks can create surrealistic landscapes.
Basalt, as volcanic igneous rock, can create unrealistic landscapes that fascinate people all over the world.
Due to the rapid cooling of the basaltic lava and its specific chemical composition, that type of volcanic igneous rock solidifies in a special hexagonal geometrical shape called columnar jointing. Svartifoss waterfall, Stuðlagil canyon, and Reynisfjara beach in Iceland are the most breathtaking examples.
Iceland basalt columns are the result of this rapid cooling process that changes the chemical makeup and appearance of the lava. Basalt volcanic rock has a special geometrical shape due to this change in composition.
The basalt pillars and hexagonal rock formations you can observe in Iceland have a special feature called columnar jointing. This is what gives each basalt column their unmistakable hexagonal shape and makes them so neat to look at.
Interesting Fact: The best igneous rock for road construction.
Previously described basaltic rock (extrusive igneous rock) – is a very popular material for paved roads construction. Since ancient Roman times, when Roman engineers used basalt to pave a lot of Roman roads, till the present day, basalt is the most common construction material for paved roads.
Scientific Fact: Pegmatites are a source of giant gemstones.
Pegmatites are crystalline igneous rocks that are distinguished by their large-size crystals. The gem minerals occur in open cavities or “pockets” within the pegmatite. The largest crystals ever found have come from pegmatites: 18-m-long beryl crystal and a 300-kg transparent gem topaz.
As the main magma body cools, water originally present in low concentrations becomes concentrated in the molten rock because it does not get incorporated into most minerals that crystallize.
Consequently, the last, uncrystallized fraction is water-rich. It is also rich in other unusual elements (lithium, beryllium, boron) that also do not like to go into ordinary minerals.
When this unusual magma is expelled in the final stages of crystallization of the magma, it solidifies to form a pegmatite.
The high water content of the magma makes it possible for the crystals to grow quickly, so pegmatite crystals are often large. Of course, this is important for gem specimens formation also!
TIP: Three main types of rocks exist on the Earth. Sedimentary, metaporphic and igneous rocks. Do you know what the differences between sedimentary and igneous rocks are? Check them out in the article below:
It’s not a surprise that igneous rocks have a high mining potential. They are so essential for industry and science, so it would be a crime not to mention their metal potential here.
Igneous rocks are also a source of precious and base metals. Platinum, palladium, and chromium are commonly extracted from mafic-ultramafic igneous rocks. Granitic igneous rocks can be perspective for tungsten extraction. Rhyolites can be a source of tin. Rhyodacite and dacite have uranium potential.
Fun Fact: Texture of igneous rock, which looks like a plant.
Spinifex textures are a striking feature of ultramafic to mafic igneous rocks. The texture has a superficially similar appearance to spinifex grasses (Trioda sp.), after which the texture was named. It is typical for rocks where the olivine or pyroxene crystals cool in the presence of a thermal gradient.
Spinifex textures are largely restricted to Archean komatiites and komatiitic basalts – igneous rocks. Komatiite samples are of great scientific value because they are extremely rare.
Weird Fact: Igneous rocks formation time.
How long does it take for igneous rock to form? We will give you a response, however, you will be surprised by the period.
Intrusive igneous rocks, which solidify deep beneath the surface, can be formed from thousands to millions of years. Extrusive (volcanic) igneous rocks can be formed rapidly. It can take from 20 minutes up to several days for extrusive rocks, which are formed as a result of lava cooling on the surface.
BTW: Do you want to know more about rock and mineral identification? The books listed below are the best ones you can find on the internet (Amazon links):
- Smithsonian Handbooks: Rocks & Minerals
- Gemstone & Crystal Properties (Quick Study Home)
- Ultimate Explorer Field Guide: Rocks and Minerals (National Geographic Kids)
Cool Fact: Igneous rocks in your kitchen.
Igneous rocks have several physical properties that ideally fit to be used in interior and functional constructions.
Even though igneous rocks have high mineral and gemstones potential, they can be also used in a design. Igneous rocks are extremely hard, durable, and aesthetically pleasing, so they can be widely used as a countertop or tiles in your kitchen. Granites, gabbros, and anorthosites rocks are commonly used rocks.
TIP: Do you know what the main characteristics of igneous rocks? Check their main characteristics in the article below:
The 6 Main Characteristics of Igneous Rocks
Weird Fact: Floating rocks.
The lightest rock on the earth, which can float on the water surface, is pumice. Pumice is a fine-grained volcanic igneous rock, which contains a lot of empty gas bubbles – vesicles. It is produced when lava goes through rapid cooling and loss of gases. It is very light grey to medium grey in color.
Pumice is also considered an extrusive (volcanic) igneous rock. Composition ranges from high-silica (rhyolitic) to low-silica (basaltic), but in most cases, pumice is in the rhyolite range.
Fun Fact: Pumice raft.
This fun fact is also related to pumice but categorized as fun because it is really hard to imagine a floating rocky island.
A pumice raft is a floating raft of pumice created by some eruptions of submarine volcanoes or coastal subaerial volcanoes. A very large pumice raft with an estimated area of 26,000 square kilometers appeared near New Zealand in August 2012. A possible source for the pumice was the Havre seamount eruption.
Conclusion
As we can see from the above, igneous rocks are not only the source of gemstones and precious metals but also a box of surprises.
Igneous rocks can form thousands of square kilometers of floating islands and can settle down in your house as a kitchen countertop. Igneous rocks can have intriguing unique textures, which resemble plants, and can form unbelievable surrealistic landscapes.
Igneous rocks are a primary source of diamonds and geodes. Both intrusive and extrusive igneous rocks are thoroughly studied by geologists and are extremely important to science. At the same time, they look so appealing, so artists commonly use them to create some art objects.
We are not mistaken when we say that igneous rocks are present in almost every sphere of our life.
We are constantly using rare elements extracted from igneous rocks as conductors and battery elements of our mobile phones. Do you still want to disagree? Please, look down. Most probably, you are staying on granite or basalt.
TIP: Do you know what the rarest gemstones on the Earth are? You will be suprised when you check them. Find out more in the article below:
13 Rarest Gemstones on Earth: You will be Shocked!
FAQs
What are 10 facts about igneous rocks? ›
- Igneous rocks are formed in molten magma.
- There are two types of igneous rock. ...
- Igneous rock is also formed when magma cools and crystallises into a rock formation.
- Most of the earth's crust is made out of igneous rock.
- Many mountains are made out of igneous rocks.
Igneous rocks are “fire-born,” meaning that they are formed from the cooling and solidification of molten (melted) rock. The word igneous derives from ignis, the Latin word for “fire.” Molten rock material is known as magma until it is erupted onto the surface when it then is termed lava.
What are igneous rocks question answer? ›Igneous rocks (from the Latin word for fire) form when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface.
What are 3 things igneous rocks used for? ›Uses of igneous rocks.
Polished granite is commonly used to make countertops. Furthermore, basalt is a staple rock in the construction industry. It is an ingredient in concrete. Pumice is also an ingredient in lightweight construction materials.
4.28 billion years old.
What are igneous rocks 11th? ›Answer. Igneous rocks are those rocks which are formed through the cooling and solidification of magma or lava. These rocks are formed when magma in its upward movement cools and turns into solid form. The process of cooling and solidification can happen in the earth's crust or on the surface of the earth.
What is igneous facts for kids? ›Igneous rock is composed of crystals or is glassy. It is formed from magma—molten or partially molten rock in the interior of Earth where temperatures are very hot. Magma exists at temperatures of 1,100° to 2,400° F (600° to 1,300° C).
Is igneous the oldest rock? ›Igneous rocks are the oldest rocks, while metamorphic are being derivative of igneous rocks and sedimentary rocks. 2. Resistance to weathering and erosion is less to metamorphic rocks compared to igneous rocks. 3.
What are 3 characteristics of igneous rocks? ›- The igneous form of rocks does not include any fossil deposits. ...
- Most igneous forms include more than one mineral deposit.
- They can be either glassy or coarse.
- These usually do not react with acids.
- The mineral deposits are available in the form of patches with different sizes.
Igneous rocks are also known as magmatic rocks. Igneous rocks are divided into two types: plutonic and volcanic rock.
Why is it called igneous rock? ›
Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there.
How do igneous rocks form *? ›Igneous rocks form when hot, liquid magma from inside the Earth cools and becomes solid. When this happens below ground, the rocks are called intrusive. When magma comes to the surface as lava and cools above ground, the rocks are called extrusive.
Why is igneous important? ›Igneous rocks are also very important because their mineral and chemical makeup can be used to learn about the composition, temperature and pressure that exists within the Earth's mantle. They can also tell us much about the tectonic environment, given that they are closely linked to the convection of tectonic plates.
What is the most used igneous rock? ›Granite: the most common igneous plutonic rock. Contains essential quartz, plagioclase and alkali feldspar, usually with hornblende and/or biotite and/or muscovite.
Why is igneous rock useful? ›Igneous rocks have a wide variety of uses. One important use is as stone for buildings and statues. Diorite was used extensively by ancient civilizations for vases and other decorative artwork and is still used for art today (Figure 1).
Do igneous rocks break easily? ›Igneous rocks are formed from molten rock called magma. They are mostly crystalline (made up of interlocking crystals) and usually very hard to break.
Is igneous rock rare? ›An ultramafic , fine-grained ( extrusive ) igneous rock. This rock will form from rapidly cooling lava , but it is very rare. Molten ultramafic rock was more prevalent on early Earth, and it can be found in the mantle.
Who discovered igneous rocks? ›The rock was described by Moore and Hayness (1920, pp. 183-187) and they gave credit for its discovery to T. S. Harrison of Denver, Colo. The rock is an igneous breccia or aglomerate comprising a ground-mass of basalt and inclusions consisting principally of shale in various stages of alteration.
What is a rock class 11? ›Any natural mass of the mineral matter that make up the Earth's crust is called a Rock. The three types of rocks are Igneous Rock, Sedimentary Rock, Metamorphic Rock.
What do igneous rocks have? ›Igneous rocks are formed from the solidification of magma, which is a hot (600 to 1,300 °C, or 1,100 to 2,400 °F) molten or partially molten rock material. Earth is composed predominantly of a large mass of igneous rock with a very thin veneer of weathered material—namely, sedimentary rock.
What is rock cycle class 11? ›
The rock cycle is the process by which rocks of one kind change into rocks of another kind. There are three main kinds of rocks: igneous rock, metamorphic rock, and sedimentary rock.
Are igneous rocks hard or soft? ›When magma crystallizes under Earth's surface, it produces intrusive igneous rock with large crystals. When lava crystallizes above Earth's surface, it produces extrusive igneous rock with crystals that are too small to see. Igneous rocks are very hard and made of interlocking crystals.
What are the 3 main types of igneous rocks? ›Igneous Rocks. When molten rock, or melted rock, solidifies, igneous rocks are formed. There are two types of igneous rocks: intrusive and extrusive.
How is igneous in everyday life? ›One of the most common igneous rocks is granite (Figure 4.1). Granite is used extensively in building materials and making statues. Perhaps you have used a pumice stone to smooth your skin or to do jobs around the house. Pumice is another example of an igneous rock (Figure 4.2).
Do all rocks start as igneous? ›All rocks are sedimentary first, then changes can happen from there to make igneous and metamorphic rocks. Metamorphic rocks are at the beginning of the rock cycle because they come from deep within the crust. All rocks originate as igneous rocks.
Which rock is the youngest? ›So recently formed igneous rock is the youngest form of rock in most circumstances. Another major classification of rock, sedimentary rock, also forms from older rock and is younger as a result.
Which rock formed first on Earth? ›The oldest rocks exposed on Earth are nearly 4.0 billion years old. These metamorphic rocks — the Acasta gneisses — are found in Canada. It is probably no coincidence that the oldest rocks found are those that formed as the rate of asteroid bombardment in our solar system slowed.
Do igneous rocks have layers? ›Answer and Explanation: No, igneous rocks do not have layers. Layering in rocks is create through two principle means, the first of which is deposition. When sediments are deposited in layers and then compacted, those layers are maintained in the resulting rock.
How do you identify an igneous rock? ›Igneous rocks can be distinguished from sedimentary rocks by the lack of beds, lack of fossils, and lack of rounded grains in igneous rocks, and the presence of igneous textures.
What is the structure of igneous rock? ›The structure of an igneous rock is normally taken to comprise the mutual relationships of mineral or mineral-glass aggregates that have contrasting textures, along with layering, fractures, and other larger-scale features that transect or bound such aggregates.
What word is igneous related to? ›
The word 'igneous' is derived from a Latin word 'ignis' meaning fire. Igneous rocks are known as primary rocks as they are formed through the cooling and solidification of magma or lava.
Is igneous a stone? ›Igneous rock (derived from the Latin word ignis meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava.
Where is igneous rock found? ›Where Igneous Rocks Are Found. The deep seafloor (the oceanic crust) is made almost entirely of basaltic rocks, with peridotite underneath in the mantle. Basalts are also erupted above the Earth's great subduction zones, either in volcanic island arcs or along the edges of continents.
Why do igneous rocks have holes? ›Vesicles are the small holes left behind after lava cools and turns into volcanic rock. Vesicles help geologists understand the cooling history of extrusive (volcanic rocks) because lava contains large amounts of dissolved gases that are released as the lava hardens.
Is igneous rock a mother rock? ›Igneous rock is popularly known as primary rocks or mother rocks because all other rocks are directly or indirectly formed from Lava and Magma. Lava and Magma are the materials which are found under the earth surface. When this magma reaches the earth surfaces it is called lava.
How does igneous turn into? ›Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock. Igneous rock forms when magma cools and makes crystals.
Is igneous rock stronger? ›Metamorphic rocks are almost always harder than sedimentary rocks. They are generally as hard and sometimes harder than igneous rocks.
What happens to igneous rocks? ›On the surface, weathering and erosion break down the igneous rock into pebbles, sand, and mud, creating sediment, which accumulates in basins on the Earth's surface. As successive layers of sediment settle on top of one another, the sediment near the bottom is compressed, hardens, and forms sedimentary rock.
What color is igneous rock? ›Felsic igneous rocks, as a whole rock, tend to have light colors or shades: white, pink, light brown, light gray. Mafic igneous rocks, on the whole, tend to be dark colored, commonly black or dark gray.
What is the largest of all igneous? ›Detailed Solution. BATHOLITH - a very large igneous intrusion extending to an unknown depth in the earth's crust. SSC CGL Tier-II Exam Dates Out (2022 cycle)!
What igneous rock is most durable? ›
Granite is one of the most durable igneous rocks.
What is the lightest igneous rock? ›What is the lightest igneous rock? Pumice is a light-colored and lightweight igneous rock ejected from a volcano at very high heat and pressure. Gases escape as the rock hardens, leaving bubbles and holes throughout the rock, and resulting in its light weight.
What are 10 facts about rocks? ›- There are three different types of rock. ...
- Rocks are made of minerals. ...
- Igneous rock comes from molten magma. ...
- Sedimentary rock is very common. ...
- Metamorphic rock has been put under a lot of pressure and heat. ...
- Geology is the study of the rocks. ...
- Space rocks land on Earth!
Igneous rocks can be divided into four categories based on their chemical composition: felsic, intermediate, mafic, and ultramafic. The diagram of Bowen's reaction series (Figure 7.6) shows that differences in chemical composition correspond to differences in the types of minerals within an igneous rock.
What are 4 characteristics of igneous rocks? ›- The igneous form of rocks does not include any fossil deposits. ...
- Most igneous forms include more than one mineral deposit.
- They can be either glassy or coarse.
- These usually do not react with acids.
- The mineral deposits are available in the form of patches with different sizes.
- Colour.
- Streak.
- Hardness: Moh's scale of hardness.
- Cleavage.
- Fracture.
- Luster.
Rocks at the surface of the earth are of many different ages. They range from over three billion years old to less than one million years old. We know that one of the laws of physics is that under ordinary circumstances matter can neither be created or destroyed.
How many igneous rocks are known? ›As hot, molten rock rises to the surface, it undergoes changes in temperature and pressure that cause it to cool, solidify, and crystallize. All told, there are over 700 known types of igneous rock , the majority of which are formed beneath the surface of the Earth's crust.
Was igneous the first rock? ›Igneous rocks are the oldest rocks, while metamorphic are being derivative of igneous rocks and sedimentary rocks. 2. Resistance to weathering and erosion is less to metamorphic rocks compared to igneous rocks. 3.
How does igneous rock get its name? ›Igneous rock (derived from the Latin word ignis meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava.
What are the 6 main types of igneous rocks? ›
The six main types of textures are phaneritic, aphanitic, porphyritic, glassy, pyroclastic, and pegmatitic.
Do igneous rocks have holes? ›Some volcanic igneous rocks cool so rapidly that crystals do not develop at all. These form a glass, such as obsidian. Others, such as pumice, contain holes where gas bubbles were trapped when the material was still hot and molten. The holes make pumice so light that it actually floats in water.