0
Why do some igneous rocks have larger crystals but other igneous rocks have crystals so small they have to be seen with a microscope?
Crystal size in igneous rock is dependent on the amount of time spent in cooling from magma or lava. More time means larger crystals. Rocks that have small crystals cooled quickly, so the minerals didn't have time to rearrange and form large crystals before the rock solidified. These small-crystalled rocks are described as aphanitic. Other rocks cooled slowly, so the minerals had time to rearrange and form large crystals before solidifying. These rocks are considered phaneritic. Some rocks cool slowly for a while, and then experience rapid cooling (such as magma that cools slowly inside a volcano, and then cools rapidly when the volcano erupts). Such rocks have large crystals surrounded by tiny crystals. Rocks that form this way are described as porphyritic.
What else can I help you with?
What chemical property is most commonly used to classify igneous rock List two physical properties that you could use to identify igneous rocks.?
The most commonly used chemical property to classify igneous rocks is their mineral composition, particularly the relative amounts of silica and other oxides present. Two physical properties that can help identify igneous rocks are texture (such as grain size and arrangement of crystals) and color, which can indicate the mineral content and cooling history of the rock.
What are other kinds of rocks?
other kinds of rocks are sedimentary rock or igneous rock
Do you need to have a seed crystal to make other crystals?
No you can make some crystals with table salt by making a saturated solution look how to do it on line
What are the three types of rock and their formation?
there are 4 bill bob and jerry and the one in abi's head she likes to call a brain Igneous, Sedimentary, and Metamorphic.
Describe how an igneous rock may become transformed into other rock types and back into igneous rock?
Describe how an igneous rock may become transformed into other rock types and back into igneous rock? The Igneous Rock would have to go through many stages known as the Rock Cycle. The Rock Cycle steps would be: Igneous Rock than it would have to go threw erosion to become a Sedimentary Rock than it would have to go through Heat and Pressure to become a Metamorphic Rock. Then The Metamorphic Rock would have to go through melting to become a Molten Rock (Lave/Magma). Then finally it would have to go through cooling to become a Igneous Rock again<3[: ---♥PandaBabby69♥
What determines how large the crystals in an igneous rock will be?
The cooling rate of magma determines the size of crystals in an igneous rock. Slow cooling allows larger crystals to form, while rapid cooling results in smaller crystals or a glassy texture. Other factors such as mineral composition and amount of available space for crystal growth also influence crystal size.
What determines how large the crystals and an igneous rock Will be?
The speed at which the magma/lava cools ie. fast cooling = not much time for crystals to form = little or no small crystals slow cooling = much time for crystals to form = big crystals
What controls the grain size of igneous rock?
The cooling rate of magma primarily controls the grain size of igneous rock. Faster cooling results in smaller grains, while slower cooling leads to larger grains. Other factors that can influence grain size include the composition of the magma and the amount of gas or water present during solidification.
What texture is igneous?
igneous is the texture of igneous rocks. The texture of igneous rocks is defined by 3 ways: a) Crystallinity- it expresses the degree of formation of crystals in an igneous rock. the texture of an igneous rock may be Holocyrstalline (Completely characterised by crystals, Hemicrystalline (partially having crystals) and holocrystalline (no crystals). b) Granularity- it is the size of the grains. it may be equigranular (when mineral grains are equal in size) or inequigranular (when mineral grains are not equal in size). c) shape of crystals- The shape of crystals may be Euhedral (When all crystals are of same shape), Subhedral (when they are partially similar in shape), Anhedral (when they are completely different in shape).
What determines crystal size in an igneous rock?
It depends on the cooling of lava. Slow cooling forms big crystals deep under the surface while fast cooling creates small crystals on or just below the earths surface. Itstant cooling wouls have no crystals.
What kind of rock forms when magma intrudes into other rocks?
Intrusive igneous rocks. These have large crystals because it is warmer underground, therefore it has more time to cool, therefore the crystals have more time to form and grow, thus large crystals.
Why does Granite take much longer to form than Basalt?
hmmm, granite is intrusive, formed and cooled slowly at depth with larger individual crystals. Basalt is extrusive, fine grained (small crystals and cooled quickly. The intrusive equivalent of basalt is gabbro. For granite; rhylolite
What factor determines if an igneous rock has no crystals small crystals or large crystals?
The rate at which the magma cools determines the size of crystals in an igneous rock. Slow cooling allows for large crystals to form, while rapid cooling results in small or no crystals. Other factors such as mineral composition and pressure can also influence crystal size.
Why is there no quartz formed in magma after it has cooled?
If you can't see its crystals without a microscope it's because the rock solidified too rapidly for visible crystals to form. Whether or not quartz is found in cooled magma/lava is basically a product of the chemical makeup of the molten rock. Quartz is the predominate silicate mineral in felsic igneous rocks, but may be non-existent in mafic igneous rocks. If you are referring to the fact that most felsic igneous rocks containing quartz do not exhibit well formed quartz crystals, it is because quartz is one of the last minerals to crystallize from magma, and solidifies in the voids between other minerals that have already crystallized.
Do intrusive igneous rocks form when lava cools and hardens on the surface of the earth?
No, they do not form on the surface of the Earth. They are formed by the crystallization of magma within the Earth. All you have to remember is an intrusive rock forms within the Earth.
What is the best evidence for determining the cooling rate of an igneous rock during its solidification is provided by what?
The best evidence for determining the cooling rate of an igneous rock during its solidification is provided by examining the size and distribution of mineral crystals within the rock. Fast cooling rates result in smaller crystals, while slow cooling rates result in larger crystals. Other indicators can include the presence of chilled margins, which are fine-grained outer edges of the rock that form during rapid cooling.
What is the difference between intrusive and igneous rocks?
The difference between an Extrusive and Intrusive igneous rock is the way in which they cool. An Extrusive igneous rock cools very fast on the surface and is created by lava. Since the cooling process is very fast extrusive igneous rocks have very small crystals (fine grained). On the other hand an Intrusive igneous rock cools very slowly beneath the surface and is created by magma. Since the cooling process is very slow intrusive igneous rocks have very large crystals (coarse grained). In some instances there is also a third type of igneous rock. Technically it is an extrusive rock, but it resembles glass. This glass type of igneous rock forms when magma/lava is instantly cooled.
