Question

How does crystal size compare in extrusive vs. intrusive rock? Explain the cause of this difference.
@AnswerMyQuestions @coolman500

Answer 1

Hang on one sec

Answer 2

ok

Answer 3

I'm not sure. :C

Answer 4

http://hyperphysics.phy-astr.gsu.edu/hbase/geophys/intrus.html try this link

Answer 5

http://www.quora.com/What-are-the-most-visible-differences-between-extrusive-and-intrusive-igneous-rocks or this one

Answer 6

I found some good info

Answer 7

@AnswerMyQuestions If you don't know than why are you here

Answer 8

@geny55 Are you still here

Answer 9

yea

Answer 10

did you check out the links

Answer 11

can you explain to me the answer in your own words please

Answer 12

ya one minute

Answer 13

Both are formed from the crystallization of minerals caused by the cooling of magma. right

Answer 14

So Intrusive igneous rocks cooled below the surface of the planet, however, and generally display larger crystals due to the increased amount of time spent at mineral crystallization temperatures from the insulating effect of surrounding material.Such as granite, gabbro, diorite, peridotite.

Answer 15

Extrusive rocks are formed from magma at or above the surface of the planet, and generally display smaller mineral crystals, or no crystals at all, because of the rapid cooling environment in which they form. Chemically, an intrusive and extrusive rock could be identical, the only difference being the size of the mineral crystals they contain.

Examples: obsidian, rhyolite, pumice, scoria, basalt.

Answer 16

Is that enofe info

Answer 17

@coolman500 He tagged me. =_=

Answer 18

@geny55 are you there

Answer 19

@coolman500
thanks for the info but what i need to know is how does the crystal size compare in extrusive an intrusive rock

Answer 20

and it has to be a brief and detailed answer. :)

Answer 21

one sec

Answer 22

kk

Answer 23

Intrusive vs. Extrusive
Igneous rocks can be classified into two main categories: intrusive and extrusive. A trick to help kids remember intrusive and extrusive is to think of intrusive -- inside and extrusive -- exit.

Answer 24

Intrusive rocks come from magma. They cool slowly deep in Earth's crust. When magma cools underground, the crust acts like a blanket, insulating it, keeping it warm longer. Because the magma cools slowly, crystals of different minerals have time to grow. The molecules in the magma have time to arrange themselves into crystal formations before the magma hardens. Intrusive rocks have large crystals that can be seen with the naked eye. A common example of an intrusive igneous rock is granite.

Answer 25

Extrusive igneous rocks come from lava. Lava, at the surface, is exposed to air and water which causes the molten rock to cool rapidly. Solidifying rocks at the surface cool too quickly for large crystals to form. Molecules in the lava do not have time to arrange themselves to form large crystals. Extrusive rocks have crystals that are too small to see without magnification. A common example of an extrusive igneous rock is basalt. Some extrusive rocks, such as obsidian and pumice, cool so rapidly that they completely lack crystal structure and are considered a volcanic glass. Pumice is just like obsidian except it is tiny shards of glass.

Answer 26

Chemical composition of igneous rock can often be estimated just from looking at the rock. Geologists look at the proportions of light-colored and dark-colored minerals in an igneous rock to estimate the chemical makeup of rock. Light-colored or felsic, minerals have more silica in them. Silica is one of the most abundant elements on Earth and is the chief component of quartz. Felsic minerals are most often colorless, white, gray or pink but can be any number of colors. The dark, or mafic, minerals are richer in iron and magnesium. Mafic minerals are chiefly black, brown, dark gray and sometimes green.

The mineral proportions of the rock are what allows geologists to classify rocks chemically. Depending on the proportion of light minerals to dark minerals, igneous rocks can be broken into four main types: felsic, intermediate, mafic and ultramafic. The following list gives more information about igneous chemical categories.

Felsic rocks are high in silica (65% +). They are usually light-colored. Some examples are: Rhyolite (extrusive) and granite (intrusive).
Intermediate rocks have lower silica content (55-65%). They are darker than felsic rocks but lighter than mafic rocks. Some examples are: Andesite/dacite (extrusive) and diorite/granodiorite (intrusive).
Mafic rocks have low silica content (45-55%). They are usually dark-colored and contain iron and magnesium. Some examples are: Basalt (extrusive) and gabbro (intrusive). Basalt is the rock that is produced at spreading ridges and makes up the sea floor.
Ultramafic rocks have extremely low silica content (less than 45%) and contain large amounts of iron and magnesium. They are usually dark-colored, but high olivine content can lend green shades to the rock. Other rare colors can be found. An example of ultramafic rock is Peridotite (intrusive).

Answer 27

ok thanks :)

Answer 28

your welcome and thanks for the medal

Answer 29

np