What are 7 types of igneous rocks?

Question

It would be better if you gave me more than 7.

Answer 1

IGNEOUS ROCKS
| Granite | Basalt | Obsidian | Pumice

Igneous rocks
are formed from molten magma or lava. The word, igneous means "fire". All igneous rock starts deep in the earth as hot, molten magma. If the magma cools and hardens inside the earth it is called "intrusive" rock. These rocks cool slowly and have large crystals. When the magma comes out of the earth's crust through a volcano, it is called "extrusive". It cools off quickly, and the crystals that form are very small. Molten, or hot, liquid rock is called MAGMA when it is still inside the earth, but once it comes out through a volcano it is called LAVA.



Granite
Granite is one of the most common rocks on our planet. It is an igneous rock that was formed from hot, melted rock called magma. The hot, liquid rock is called magma while it remains underground and is called lava when it comes out of the earth's crust during a volcanic eruption. The hot magma cools underground and hardens into solid rock. Granite is made up mostly from a mixture of quartz, feldspar and mica crystals. It has large crystals that you can see very easily. The black specks that you can see in the picture are crystals of mica

Basalt is another example of an igneous rock. It is formed during volcanic eruptions from the hot lava coming out of a volcano. Basalt is the most common type of rock that is formed from lava. It's crystals are so small that they are not easily seen, even with a magnifing lens. Lava cools quickly above ground and forms very small crystals. When Magma cools slowly underground, large crystals are formed. The Hawaiian Islands and most of the ocean floor are made up of basalt.

Obsidian
Obsidian is an igneous rock that is very different than most other types. It is formed by the very rapid cooling of lava. When certain types of lava cool this fast, it makes volcanic glass, or obsidian. The rocks are very hard and shiny, and when they break, or fracture, they have very sharp edges. Since the Stone Age, humans have used obsidian to make cutting tools and tips for their arrows and spears.



Pumice
Pumice is a very light, porous igneous rock that is formed during volcanic eruptions. It is made up of very tiny crystals, since they cool so quickly above ground. The texture of pumice is rough and has many hollows and cavities. It sort of looks like froth or foam that has hardened. In fact, it forms from frothy lava that has lots of gas bubbles trapped in it, and all those little holes used to have gas trapped in them. Because pumice has all those holes and gas pockets it is very light and can actually float in water! Sometimes a volcano erupts underwater and the pumice that is produced often floats away.



are the basic components of rocks and the most common visible substances on Earth. You are probably most familiar with minerals as the beautiful gemstones in jewelry or as masses of natural crystals displayed in museums. What you may not realize is that minerals are also the natural materials from which every inorganic (not composed of any plant or animal matter) item in our industrialized society has been manufactured. For example, the pencil you write with was made with several minerals (see figure). The walls in your home are likely made with a mineral called gypsum, the glass with quartz, and the pipes with copper (see display cabinet 59 in McGilvrey hallway directly outside the lab room).

There are more than 3000 different minerals! A mineral by definition must be

solid
naturally occurring
have a characteristic chemical composition (Quartz is SiO2)
have a definite internal atomic arrangement.
In spite of the very large number minerals that exist, there are really only about 20 or so that are very common and that make up rocks (which are aggregates of minerals). The reason that there are only about 20 rock-forming minerals is because the Earth's crust (the outermost rocky portion of the Earth) is made up mostly of only 8 elements (from the periodic table of elements: see table below).

Major Elements in the crust of the Earth

Element Volume proportion

Oxygen (O) 93.7%
Potassium (K) 1.8%
Sodium (Na) 1.3%
Calcium (Ca) 1.0%
Silicon (Si) 0.8%
Aluminum (Al) 0.5%
Iron (Fe) 0.4%
Magnesium (Mg) 0.3%
Because they are so important geologist's sometime refer to these elements as the BIG 8. They are easy to remember if you make a mnemonic like the following: Only strong athletes in college study past midnight. (Oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium).

Elements combine to form minerals (Si and O combine to form quartz).
Minerals combine to form rocks (quartz and feldspar combine to form granite).

KSU's Geology Department offers an entire course on the study of minerals (Mineralogy) but for this lab we will focus on 10-12 rock forming minerals and the physical properties used to identify them. Display cabinet 64 in the hallway shows many of the physical mineral properties including color, streak (its appearance in powdered form), hardness (resistance to being scratched), luster (its appearance in reflected light), cleavage (tendency to break along certain planes), and density.

For instance, hardness is one of the more useful identifying properties for a mineral. Geologist's have a scale (the Moh's hardness scale) which ranks some common minerals from 1 to 10:

Talc (the softest of all minerals)
Gypsum - Fingernail (2.5)
Calcite - Penny (3.5)
Flourite
Apatite - Nail (soft steel) 5 or Glass or knife blade (5.5)
Orthoclase feldspar
Quartz - Ceramic streak plate (7)
Topaz
Corundum
Diamond! (the hardest of all minerals)

Again, can you think of a funny mnemonic to help you remember the Moh's hardness scale? (write it here for future reference).

You can see examples of various minerals at The Mineral Gallery Web Site: view minerals by type.


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Introduction to Igneous Rocks

Very often isolated mineral specimens look very different from how they appear in rocks. For this reason we will also show you what minerals look like in rocks during this lab. There are only three types of rocks:

Igneous = a rock which forms by minerals crystallizing out from a melt.
Sedimentary = a rock which forms from the breakdown of other rocks.
Metamorphic = a rock which has undergone a change in temperature and pressure.

theres all i can do for you theres 4 rocks up there at least hope the links help you

Answer 2

List Of Igneous Rocks

Answer 3

ahhh geology homework.... brings back so many memories 7 questions & you dont know any of them... I'll give you the answers, but unless you understand them it wont help you learn... and no I wont deliberately give you the wrong ones 1 plutonic as the magma cools slowly allowing time for large crystals to grow 2 option 1 - look up the definitions of igneous, metamorphic and sedimentary rocks to find out why 3 Basalt 4 true 5 Gabbro - look it up to find out why 6 volcanic. plutonic means intruded into the earth's crust but not erupted 7 ionic van der waals are bond between molecules not bonds that form them covalent bonds are where electrons are shared between atoms ionic are where elecrons are 'donated' from a positive valence atom to a negative valence atom. Ionic and covalent bonds are similar in strength but ionic are slightly stronger now go & study!!!!!

Answer 4

From Wikipedia:

Over 700 types of igneous rocks have been described, most of them formed beneath the surface of the Earth's crust.

Much much more (too much to copy here) at:

http://en.wikipedia.org/wiki/Igneous_rock

Answer 5

Granite
Obsidian
Basalt/Dacite
Pumice
Andesite
Diorite
Rhyolite
Gabbro
Snowflake Obsidian
Diabase
Scoria
Peridotita
Pegmatite
Komatite
Volcanic Agglomerates

hope this helps

Answer 6

Granite, rhyolite, diorite, andesite, gabbro, basalt, dunite.

Answer 7

do your own homework