
There are three types of rocks:
- Igneous Rocks
- Sedimentary Rocks
- Metamorphic Rocks
How many types of rocks are there?
There are three types of rocks: 1 Igneous Rock. Igneous rock is one of the three main rock types. Igneous rock is formed through the cooling and solidification of magma or lava. 2 Types of Igneous Rock. 3 Igneous Rock Examples. 4 Sedimentary Rock. 5 Types of Sedimentary Rock. More items
What are the types of rocks in your collection?
The types of rocks are: Igneous; Sedimentary; Metamorphic; To help you identify the types of rocks in your collection, let’s look at the characteristics that make up the three types. First, we will look at igneous rocks.
What are the different types of rocks in national parks?
Rocks are divided into three basic types depending on how they were formed: Igneous, Sedimentary, and Metamorphic. Natural objects, such as rocks and minerals, contribute to the beauty and wonderment of the National Parks and should be left, as they were found, so that others can experience a sense of discovery.
What are the two types of igneous rocks?
Types of Igneous Rock. Following are the two types of igneous rock: Intrusive igneous rock: These rocks crystallize below the earth’s surface resulting in large crystals as the cooling takes place slowly. Diorite, granite, pegmatite are examples of intrusive igneous rocks.

What are the 3 different types of rocks?
3 Types of Rock: Igneous, Sedimentary & Metamorphic | AMNH.
What are the different types of rocks and their uses?
LIMESTONE: A sedimentary rock, it is used mainly in the manufacture of Portland cement, the production of lime, manufacture of paper, petrochemicals, insecticides, linoleum, fiberglass, glass, carpet backing and as the coating on many types of chewing gum. SHALE: A sedimentary rock, well stratified in thin beds.
How do you identify different types of rocks?
2:454:35How to identify the different types of rocks - YouTubeYouTubeStart of suggested clipEnd of suggested clipAnd look less shiny than crystalline igneous and metamorphic rocks you cannot tell a rock type byMoreAnd look less shiny than crystalline igneous and metamorphic rocks you cannot tell a rock type by its colour. Alone but certain colours can be used to infer a rock's chemistry.
What are the classifications of different rocks and its characteristics?
These classes are (1) igneous rocks, which have solidified from molten material called magma; (2) sedimentary rocks, those consisting of fragments derived from preexisting rocks or of materials precipitated from solutions; and (3) metamorphic rocks, which have been derived from either igneous or sedimentary rocks under ...
What are 5 sedimentary rocks and their uses?
Oil, natural gas, coal, and uranium, our major energy resources, are formed in and come from sedimentary rocks. Sand and gravel for construction come from sediment. Sandstone and limestone are used for building stone. Rock gypsum is used to make plaster.
What are the uses of rocks give at least 3 answer?
For paving and roofing in the form of flags or thin slabs. For masonry works, lintels, covering floors and building construction. To exact valuable minerals like Gold, Sapphire, Diamond etc.
What are the main uses of igneous rocks?
People use granite for countertops, buildings, monuments and statues. Pumice is also an igneous rock. Perhaps you have used a pumice stone to smooth your skin. Pumice stones are put into giant washing machines with new jeans and tumbled around.
What are sedimentary rocks used for?
Uses of Sedimentary Rocks Limestone is used to make cement. Quartz is a type of sedimentary rock which is used to make glass. Rock gypsum is used to make plaster. Natural gas, oil, coal, uranium, and other energy resources are formed in and come from sedimentary rocks.
What are rocks?
Rocks are mineral aggregates with a combination of properties of all the mineral traces. Any unique combination of chemical composition, mineralogy...
What are the different types of rocks?
There are three types of rocks: Igneous Rocks Sedimentary Rocks Metamorphic Rocks
Which is the most common type of igneous rock?
Basalt is the most common type of igneous rock. The majority of the ocean floor is composed of basalt.
Give some examples of sedimentary rocks.
Some common sedimentary rocks are: Limestone Chalk Clay Sandstone Shale
How are sedimentary rocks formed?
Sedimentary rocks are formed by the deposition and subsequent cementation on the material at the Earth’s surface within the bodies of water. These...
What are the three types of rock?
Additionally, different classification systems exist for each major type of rock. There are three major types of rock: igneous rock, metamorphic rock, and sedimentary rock .
What is the name of the mixture of metamorphic rock and igneous rock?
Migmatite – Mixture of metamorphic rock and igneous rock. Mylonite – A metamorphic rock formed by shearing. Metapelite – A metamorphic rock with a protolith of clay-rich (siltstone) sedimentary rock. Metapsammite – A metamorphic rock with a protolith of quartz-rich (sandstone) sedimentary rock.
What is the name of the rock that is found in ophiolites?
Harzburgite – Ultramafic and ultrabasic mantle rock. Found in ophiolites.
What is the name of the intermediate volcanic rock?
Adakite – A class of intermediate to felsic volcanic rocks containing low amounts of yttrium and ytterbium. Andesite – Intermediate volcanic rock. Alkali feldspar granite – A granitoid in which at least 90% of the total feldspar is alkali feldspar. Anorthosite – Mafic intrusive igneous rock composed predominantly of plagioclase.
What is the name of the rock that is made of olivine?
Dunite – An ultramafic and ultrabasic rock from Earth's mantle and made of the mineral olivine. Essexite – a dark gray or black holocrystalline plutonic rock. Foidolite – A rare coarse-grained intrusive igneous rock in which more than 60% of light-coloured minerals are feldspathoids.
What is the name of the intrusive mafic rock that forms dykes?
Diabase, also known as dolerite – An intrusive mafic rock forming dykes or sills. Diorite – Intermediate intrusive igneous rock composed principally of plagioclase feldspar. Napoleonite, also known as corsite – Variety of diorite with orbicular structure.
What is the mineral dolomite?
Dolomite (rock), also known as Dolostone – Sedimentary carbonate rock that contains a high percentage of the mineral dolomite. Evaporite – Water-soluble mineral deposit formed by evaporation from an aqueous solution. Flint – Cryptocrystalline form of the mineral quartz.
What are the different types of rocks?
In short, there are three different types of rocks that every rock you meet can be classified as. The three types of rocks are: 1 Igneous Rocks 2 Metamorphic Rocks 3 Sedimentary Rocks
Where are sedimentary rocks formed?
Sedimentary rocks are formed at the surface of the Earth. This can take place either in water or on land. Sedimentary rocks are exactly what they sound like…sediment. Sedimentary type rocks are layered accumulations of different kinds of sediments, such as fragments of rocks, minerals, and even animal and plant material.
What type of rock forms when magma reaches the Earth's surface?
Extrusive igneous rocks form when magma reaches the Earth’s surface a volcano and cools quickly. Most extrusive (volcanic) rocks have small crystals. Examples of extrusive igneous rocks include basalt, rhyolite, andesite, and obsidian.
How are igneous rocks formed?
That means that Igneous rocks are formed when molten rock from deep within the earth rises to the surface (lava) and cools. Sometimes the magma will cool inside the earth before it even reaches the surface.
What is the name of the igneous rock that is dark in color?
Obsidian – Obsidians are dense extrusive igneous rocks that are dark in color. They are created when lava cools rapidly without crystalizing. They are dark, but are clear in slim pieces, and was often times used to make arrowheads by ancient civilizations.
What are some examples of intrusive igneous rocks?
Most intrusive rocks have large, well-formed crystals. Examples of intrusive igneous rocks include granite, gabbro, diorite and dunite.
Where is shale found?
They are generally a good source of fossils and are mostly found at the bottom of lakes or oceans.
How many types of rocks are there?
Now that you’re familiar with 30 amazing types of rock, let’s talk a bit about how rocks are actually classified.
How Are Rocks Classified?
Now that you’re familiar with 30 amazing types of rock, let’s talk a bit about how rocks are actually classified.
What is anorthosite made of?
Made almost entirely out of plagioclase feldspar, anorthosite is one of the Earth’s most fascinating rocks. However, the most fascinating thing about it is totally out of this world. In fact, anorthosite is one of the oldest rocks found on the surface of the Moon!
What is the name of the rock in the Italian Alps?
Named for French geologist Déodat Gratet de Dolomieu, dolomite is one of the most iconic rock types of the Italian Alps. Found extensively throughout the mountain range that bears its name (the Dolomites), dolomite, or dolostone, is a type of sedimentary rock that mostly consists of the mineral dolomite.
What is the most attractive rock?
One of the most visually attractive types of rock, obsidian is a jet-black and smooth rock that’s long played an important role in human culture.
Which type of rock goes through transitions over time?
Each of the three main types of rock that we described above (igneous, sedimentary, and metamorphic) goes through transitions over time.
Is tuff a rock?
However, since tuff consists of consolidated sediments, it could actually be described as a sedimentary rock, too .
What are the three types of rocks?
Geologists classify rocks into three basic groups based on how they were formed in nature. The types of rocks are: Igneous. Sedimentary. Metamorphic. To help you identify the types of rocks in your collection, let’s look at the characteristics that make up the three types. First, we will look at igneous rocks.
What is a sedimentary rock?
SEDIMENTARY ROCK DERIVED FROM MUD. COMMONLY FINELY LAMINATED (BEDDED). PARTICLES IN SHA LE ARE COMMONLY CLAY MINERALS MIXED WITH TINY GRAINS OF QUARTZ ERODED FROM PRE-EXISTING ROCKS. SHALEY MEANS LIKE A SHALE OR HAVING SOME SHALE COMPONENT, AS IN SHALEY SANDSTONE. (CREDIT: U.S. GEOLOGICAL SURVEY)
What is the process of metamorphic rocks?
Sometimes sedimentary and igneous rocks are subjected to pressures so intense or heat so high that they are completely changed. They become metamorphic rocks, which form while deeply buried within the Earth’s crust. The process of metamorphism does not melt the rocks, but instead transforms them into denser, more compact rocks. New minerals are created either by rearrangement of mineral components or by reactions with fluids that enter the rocks. Some kinds of metamorphic rocks–granite gneiss and biotite schist are two examples–are strongly banded or foliated. (Foliated means the parallel arrangement of certain mineral grains that gives the rock a striped appearance.) Anyone who wishes to collect rocks should become familiar with the characteristics of these three rock groups. Knowing how a geologist classifies rocks is important if you want to transform a random group of rock specimens into a true collection. (Credit: U.S. Geological Survey)
What is a slate rock?
SLATE IS A METAMORPHIC ROCK. METAMORPHIC ROCKS ARE FORMED WHEN SEDIMENTARY OR IGNEOUS ROCKS ARE EXPOSED TO CONDITIONS OF VERY HIGH PRESSURE OR TEMPERATURE, OR ARE EXPOSED TO LARGE AMOUNTS OF VERY HOT WATER. SLATE IS FORMED WHEN FINE-GRAINED SEDIMENTARY ROCK (SHALE) IS BURIED AND EXPOSED TO HIGH PRESSURE DEEP BENEATH THE EARTH’S SURFACE. SLATE, LIKE MANY, BUT NOT ALL, METAMORPHIC ROCKS IS CHARACTERIZED BY THE WAY IT BREAKS, ALONG CLOSELY SPACED PARALLEL FRACTURES. (CREDIT: U.S. GEOLOGICAL SURVEY)
How are sedimentary rocks formed?
Sedimentary rocks are formed at the surface of the Earth, either in water or on land. They are layered accumulations of sediments-fragments of rocks, minerals, or animal or plant material. Temperatures and pressures are low at the Earth’s surface, and sedimentary rocks show this fact by their appearance and the minerals they contain. Most sedimentary rocks become cemented together by minerals and chemicals or are held together by electrical attraction; some, however, remain loose and unconsolidated. The layers are normally parallel or nearly parallel to the Earth’s surface; if they are at high angles to the surface or are twisted or broken, some kind of Earth movement has occurred since the rock was formed. Sedimentary rocks are forming around us all the time. Sand and gravel on beaches or in river bars look like the sandstone and conglomerate they will become. Compacted and dried mud flats harden into shale. Scuba divers who have seen mud and shells settling on the floors of lagoons find it easy to understand how sedimentary rocks form. (Credit: U.S. Geological Survey)
What type of rock is formed when magma cools?
When magma cools rapidly, usually at or near the Earth’s surface, the crystals are extremely small, and a fine-grained rock results. A wide variety of rocks are formed by different cooling rates and different chemical compositions of the original magma. Obsidian (volcanic glass), granite, basalt, and andesite porphyry are four of the many types ...
What does sand and gravel look like?
Sand and gravel on beaches or in river bars look like the sandstone and conglomerate they will become. Compacted and dried mud flats harden into shale. Scuba divers who have seen mud and shells settling on the floors of lagoons find it easy to understand how sedimentary rocks form.
Igneous Rocks
Adakite – Volcanic rock type Andesite – Type of volcanic rock Alkali feldspar granite – Type of igneous rock rich in alkali feldspar Anorthosite – Mafic intrusive igneous rock composed predominantly of plagioclase Aplite – Fine-grained intrusive igneous rock type similar to granite Basalt – Magnesium- and iron-rich extrusive igneous rock ʻAʻā – Basaltic lava with a crumpled appearance Pāhoehoe – Basaltic lava with a flowing, often ropy appearance Basaltic trachyandesite Mugearite – Volcanic rock type Shoshonite – Potassium-rich variety of basaltic trachyandesite Basanite – A silica-undersaturated basalt Blairmorite – Rare porphyritic volcanic rock Boninite – Ultramafic extrusive rock high in both magnesium and silica Carbonatite – Igneous rock with more than 50% carbonate minerals Charnockite – Type of granite containing orthopyroxene Enderbite – Igneous rock of the charnockite series Dacite – Volcanic rock intermediate in composition between andesite and rhyolite Diabase, also known as dolerite – Type of igneous rock Diorite – Igneous rock type Napoleonite, also known as corsite – Variety of diorite with orbicular structure Dunite – Ultramafic and ultrabasic rock from Earth’s mantle which is made of the mineral olivine Essexite – Dark gray or black holocrystalline plutonic rock Foidolite – Igneous rock rich in feldspathoid minerals Gabbro – Coarse-grained mafic intrusive rock Granite – Common type of intrusive, felsic, igneous rock with granular structure Granodiorite – Type of coarse grained intrusive igneous rock Granophyre – Subvolcanic rock that contains quartz and alkali feldspar in characteristic angular intergrowths Harzburgite – Ultramafic mantle rock Hornblendite – Plutonic rock consisting mainly of the amphibole hornblende Hyaloclastite – Volcaniclastic accumulation or breccia Icelandite – Iron rich, aluminium poor andesite Ignimbrite – Variety of hardened tuff Ijolite – Igneous rock consisting essentially of nepheline and augite Kimberlite – Igneous rock which sometimes contains diamonds Komatiite – Ultramafic mantle-derived volcanic rock Lamproite – Ultrapotassic mantle-derived volcanic or subvolcanic rock Lamprophyre – Ultrapotassic igneous rocks – An ultramafic, ultrapotassic intrusive rock dominated by mafic phenocrysts in a feldspar groundmass Latite – Type of volcanic rock – A silica-undersaturated form of andesite Lherzolite – An ultramafic rock, essentially a peridotite Monzogranite – A silica-undersaturated granite with <5% normative quartz Monzonite – Igneous intrusive rock with low quartz and equal plagioclase and alkali feldspar – a plutonic rock with <5% normative quartz Nepheline syenite – A silica-undersaturated plutonic rock of nepheline and alkali feldspar Nephelinite – Igneous rock made up almost entirely of nepheline and clinopyroxene – A silica-undersaturated plutonic rock with >90% nepheline Norite – A hypersthene-bearing gabbro Obsidian – Naturally occurring volcanic glass Pegmatite – Igneous rock with very large interlocked crystals Peridotite – Coarse-grained ultramafic igneous rock type Phonolite – Uncommon extrusive rock – A silica-undersaturated volcanic rock; essentially similar to nepheline syenite Phonotephrite – A volcanic rock with a composition between phonolite and tephrite Picrite – An olivine-bearing basalt Porphyry – Textural form of igneous rock with large grained crystals in a fine matrix Pumice – Light colored highly vesicular volcanic rock Pyroxenite – Igneous rock – a coarse grained plutonic rock composed of >90% pyroxene Quartz diorite – Igneous, plutonic rock – A diorite with >5% modal quartz Quartz monzonite – Type of igneous rock – An intermediate plutonic rock, essentially a monzonite with 5–10% modal quartz Quartzolite – Extremely rare igneous rock made mostly of quartz – An intrusive rock composed mostly of quartz Rhyodacite – Volcanic rock rich in silica and low in alkali metal oxides – A felsic volcanic rock which is intermediate between a rhyolite and a dacite Rhyolite – Igneous, volcanic rock, of felsic (silica-rich) composition Comendite – Hard, peralkaline igneous rock, a type of light blue grey rhyolite Pantellerite – Peralkaline rhyolite type of volcanic rock Scoria – Dark vesicular volcanic rock Shonkinite – Intrusive igneous rock – a plutonic rock Sovite – A coarse-grained carbonatite rock Syenite – Intrusive igneous rock – A plutonic rock dominated by orthoclase feldspar; a type of granitoid Tachylyte – Essentially a basaltic glass Tephriphonolite – A volcanic rock with a composition between phonotephrite and phonolite Tephrite – Igneous, volcanic rock – A silica-undersaturated volcanic rock Tonalite – A plagioclase-dominant granitoid Trachyandesite – An alkaline intermediate volcanic rock Benmoreite – Silica-undersaturated volcanic rock of intermediate composition – sodic trachyandesite Trachybasalt – A volcanic rock with a composition between basalt and trachyte Hawaiite – Volcanic rock – a sodic type of trachybasalt, typically formed by ocean island (hot spot) volcanism Trachyte – Extrusive igneous rock – A silica-undersaturated volcanic rock; essentially a feldspathoid-bearing rhyolite Troctolite – Igneous rock – A plutonic ultramafic rock containing olivine, pyroxene and plagioclase Trondhjemite – Light-colored intrusive igneous rock – A form of tonalite where plagioclase-group feldspar is oligoclase Tuff – Rock consolidated from volcanic ash Websterite – A type of pyroxenite, composed of clinoproxene and orthopyroxene Wehrlite – Ultramafic rock – An ultramafic plutonic or cumulate rock, a type of peridotite, composed of olivine and clinopyroxene.
Sedimentary Rocks
Turbidite (Gorgoglione Flysch), Miocene, South Italy Argillite – Sedimentary rock, mostly of indurated clay particles Arkose – Type of sandstone containing at least 25% feldspar Banded iron formation – Distinctive layered units of iron-rich sedimentary rock that are almost always of Precambrian age Breccia – Rock composed of broken fragments cemented by a matrix Calcarenite – Type of limestone that is composed predominantly of sand-size grains Chalk – Soft, white, porous sedimentary rock made of calcium carbonate Chert – Hard, fine-grained sedimentary rock composed of cryptocrystalline silica Claystone – Clastic sedimentary rock composed primarily of clay-sized particles Coal – Combustible sedimentary rock composed primarily of carbon Conglomerate – Coarse-grained clastic sedimentary rock with mainly rounded to subangular clasts Coquina – Sedimentary rock that is composed mostly of fragments of shells Diamictite – Type of sedimentary rock Diatomite – Soft, siliceous sedimentary rock that is easily crumbled Dolomite (rock), also known as Dolostone – Sedimentary carbonate rock that contains a high percentage of the mineral dolomite Evaporite – Water-soluble mineral deposit formed by evaporation from an aqueous solution Flint – Cryptocrystalline form of the mineral quartz Geyserite – Form of opaline silica that is often found around hot springs and geysers Greywacke – Hard, dark sandstone with poorly sorted angular grains in a compact, clay-fine matrix Gritstone – Hard, coarse-grained, siliceous sandstone Itacolumite – A porous, yellow sandstone or schistose quartzite that is flexible when cut into thin strips Jaspillite – Banded mixture of hematite and quartz Laterite – Product of rock weathering in wet tropical climate rich in iron and aluminum Lignite – Soft, brown, combustible, sedimentary rock Limestone – Sedimentary rocks made of calcium carbonate Marl – Lime-rich mud or mudstone which contains variable amounts of clays and silt Mudstone – Fine grained sedimentary rock whose original constituents were clays or muds Oil shale – Organic-rich fine-grained sedimentary rock containing kerogen Oolite – Sedimentary rock formed from ooids Phosphorite – Sedimentary rock containing large amounts of phosphate minerals – A non-detrital sedimentary rock that contains high amounts of phosphate minerals Sandstone – Type of sedimentary rock Shale – Fine-grained, clastic sedimentary rock Siltstone – Sedimentary rock which has a grain size in the silt range Sylvinite – A sedimentary rock made of a mechanical mixture of sylvite and halite Tillite – Till which has been indurated or lithified by burial Travertine – Form of limestone deposited by mineral springs Tufa – Porous limestone rock formed when carbonate minerals precipitate out of ambient temperature water Turbidite – Geologic deposit of a turbidity current Wackestone – Mud-supported carbonate rock that contains greater than 10% grains.
Metamorphic Rocks
Anthracite – Hard, compact variety of coal Amphibolite – A metamorphic rock containing mainly amphibole and plagioclase Blueschist – Metavolcanic rock that forms by the metamorphism of basalt and rocks with similar composition Cataclasite – A rock formed by faulting Eclogite – A dense metamorphic rock formed under high pressure Gneiss – Common high-grade metamorphic rock Granulite – Class of high-grade medium to coarse grained metamorphic rocks Greenschist – Metamorphic rocks – A mafic metamorphic rock dominated by green amphiboles Hornfels – Calcflinta – A type of hornfels found in the Scottish Highlands Litchfieldite – Nepheline syenite gneiss Marble – Non-foliated, metamorphic rock, commonly used for sculpture and as a building material – a metamorphosed limestone Migmatite – Mixture of metamorphic rock and igneous rock Mylonite – Metamorphic rock – A metamorphic rock formed by shearing Metapelite – A metamorphic rock with a protolith of clay-rich (siltstone) sedimentary rock Metapsammite – A metamorphic rock with a protolith of quartz-rich (sandstone) sedimentary rock Phyllite – Type of foliated metamorphic rock – A low grade metamorphic rock composed mostly of micaceous minerals Pseudotachylite – A glass formed by melting within a fault via friction Quartzite – Hard, non-foliated metamorphic rock which was originally pure quartz sandstone – A metamorphosed sandstone typically composed of >95% quartz Schist – Easily split medium-grained metamorphic rock Serpentinite – Rock formed by hydration and metamorphic transformation of olivine Skarn – Hard, coarse-grained, hydrothermally altered metamorphic rocks Slate – Metamorphic rock – A low grade metamorphic rock formed from shale or silts Suevite – Rock consisting partly of melted material formed during an impact event – A rock formed by partial melting during a meteorite impact Talc carbonate – A metamorphosed ultramafic rock with talc as an essential constituent; similar to a serpentinite Soapstone – Talc-bearing metamorphic rock – Essentially a talc schist Tectonite – A rock whose fabric reflects the history of its deformation Whiteschist – A high pressure metamorphic rock containing talc and kyanite.
Specific Varieties
The following are terms for rocks that are not petrographically or genetically distinct but are defined according to various other criteria; most are specific classes of other rocks, or altered versions of existing rocks. Some archaic and vernacular terms for rocks are also included.
Introduction
Rocks are all around us. They make up the backbones of hills and mountains and the foundations of plains and valleys. Beneath the soil you walk on and the deep layers of soft mud that cover the ocean basins is a basement of hard rock. Rocks are made up of different minerals, broken pieces of crystals, or broken pieces of rocks.
Related Links
Badlands National Park, South Dakota [ Geodiversity Atlas] [ Park Home]
How old are the oldest rocks in the world?
Learn about the oldest rocks found in the parks that range in age from 3 billion to 600 million years old.
Why are rocks and minerals important?
Rocks and minerals are important for learning about earth materials, structure, and systems. Studying these natural objects incorporates an understanding of earth science, chemistry, physics, and math. The learner can walk away with an understanding of crystal geometry, the ability to visualize 3-D objects, or knowing rates of crystallization.
Why is it important to learn about rocks and minerals?
Learning about rocks and minerals gives students a deeper appreciation of the story behind the scenery in our national parks.
Who discovered that different minerals crystallize at different temperatures during the cooling of magma?
In the early 1900's N. L. Bowen determined that different minerals crystallize at different temperatures during the cooling of magma. This chart demonstrates the reaction rates. Source: Trista L. Thornberry-Ehrlich, Colorado State University. [273 KB JPEG]
What grade do you study magma?
In an exploration of magma behavior, students role-play minerals that are cooling at different rates, and then examine rock samples. Student activity, Grades 4-8. Mount Rainier National Park, Washington.
Top 15 best types of landscaping rocks
Types Of Landscaping Rocks -Many people like Japanese rock gardens with pebbles as one of the best landscaping rocks because it gives them the look of still water even if they do not have an actual pond or pool.
Pros of landscaping rocks
Landscaping rocks can add a natural element to your garden that plants alone may lack. If you have just planted a flowering plant in the ground, it might not be until next spring that it sprouts enough leaves to cover up all the bare soil around it.
Cons of landscaping rocks
Although there are many benefits to using rocks in your garden, there are several cons as well. One con would be those small children may find themselves playing with them more than caring for the plants around them. Children may decide to stack the rocks and create a tower or try and balance them on top of each other.

Overview
Igneous rocks
• Adakite – Volcanic rock type
• Andesite – Type of volcanic rock
• Alkali feldspar granite – Type of igneous rock rich in alkali feldspar
• Anorthosite – Mafic intrusive igneous rock composed predominantly of plagioclase
Sedimentary rocks
• Argillite – Sedimentary rock, mostly of indurated clay particles
• Arkose – Type of sandstone containing at least 25% feldspar
• Banded iron formation – Distinctive layered units of iron-rich sedimentary rock that are almost always of Precambrian age
Metamorphic rocks
• Anthracite – Hard, compact variety of coal
• Amphibolite – A metamorphic rock containing mainly amphibole and plagioclase
• Blueschist – Type of metavolcanic rock
Specific varieties
The following are terms for rocks that are not petrographically or genetically distinct but are defined according to various other criteria; most are specific classes of other rocks, or altered versions of existing rocks. Some archaic and vernacular terms for rocks are also included.
• Adamellite – A variety of quartz monzonite
• Appinite – A group of varieties of lamprophyre, mostly rich in hornblende
See also
• List of minerals – List of minerals for which there are articles on Wikipedia
• List of rocks on Mars – Alphabetical list of named rocks and meteorites found on Mars
• Rock cycle – Transitional concept of geologic time
External links
• British Geological Survey rock classification scheme
• Igneous rock classification
• Rock Types Article by Encyclopædia Britannica
• Classification of common rocks and soils