Igneous Rocks

Judit Carreño Àlex Martín Claudia Vila

● What are igneous rocks?

● What are the different types of cooling?

● Obsidian, volcanic lava, basalt, pumice

● What are plutonic rocks?

● Syenite, granite, pink granite

● Difference between volcanic rocks and plutonic rocks

● Webgraphie

● Authors

What are igneous rocks?Igneous rocks are rocks that have been subjected to a very high temperature to melt. So, when these rocks leave to the outside, depending on how it cools, leave a type of rock or another.

What are the different types of cooling?Rocks can be cooled by a slowly cooling or a quickly cooling method, so depending on the cooling system, there can be rocks with large crystals or with small crystals. An example:

❖With the quickly cooling: Obsidian

❖With the slowly cooling: Granite

ObsidianOBSIDIAN

Form: Mineraloid

Colour: Black

Fracture: Concoidal

Texture: Vitreous

Composition: Most abundant composition: SiO2

Utility: The first use was as a cutting tool. Now, to make masks, small sculptures and figurines.

Volcanic lavaVOLCANIC LAVA

Form: Different types of formsColour: Black / GrayFracture: Either wayTexture: VitreousComposition: Intrusive and extrusive materials Utility: Used in construction.

BasaltBASALT

Form: Different types of forms

Colour: Gray, black.

Fracture: Straight

Texture:Usually they have a porphyritic texture.

Composition: Pyroxene, calcic plagioclase.

Utility: Mainly used in construction.

Pumice

PUMICEForm: Differents types of forms

Colour: Yellow, Red, Light Grey

Fracture: Straight

Texture: Vitreous

Uses: For beauty items.

Composition: Feldspat, oligoclase, albite, biotite, pyroxene.

What are plutonic rocks?Plutonic rocks are those igneous rocks that have been formed by slow cooling in depth and in large masses of magma.

GraniteGRANITE

Colour: White, pink or gray

Form: Differents types of forms

Fracture: Failures

Texture: granular and phaneritic

Composition: 74.5% silicon, 14% alumina, 9.5% of sodium and potassium oxides (Na2O, K2O) and 2% other oxides

Utility:it Is used in construction

SyeniteSYENITE

Form: Differents types of forms

Colour:White, blak and pink

Fracture: Straight

Texture: Vitreous

Composition: It is composed of orthoclase and plagioclase, with small amounts of hornblende, mica, auguita and magnetite.

Utility: Used in construction.

Pink GranitePINK GRANITE

Colour: Pink

Form: Differents types of forms

Fracture: Thick

Texture: pimpled texture

Composition:Quartz, feldspar and mica

Utility: It used in construction

Difference between volcanic rocks and plutonic rocksThe volcanic rocks are formed by the cooling of lava at the Earth’s surface or under the sea.

The plutonic rocks are formed by slow cooling in depth and in large masses of magma.

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➢ https://en.wikipedia.org/wiki/Igneous_rock

➢http://www.sciencekids.co.nz/sciencefacts/earth/metamorphicrocks.html

➢http://www.rocksforkids.com/2glossary.html

➢http://www.rocksforkids.com/3identification.html

➢http://www.rocksforkids.com/3fieldtests.html

➢http://geology.com/rocks/basalt.shtml