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What does an igneous rock's crystal grain size indicate to the observer?
Wiki User
∙ 12y ago
The size of the mineral crystals in an igneous rock is related to the rate of time spent in cooling from magma. Longer exposure to the crystallization temperature means larger crystals. Less time means smaller crystals, or in the case of obsidian, which cools extremely quickly, no crystallization.
Wiki User
∙ 12y ago
Wiki User
∙ 14y agoCrystal size is determined by the amount of time the magma or lava has to cool. Lava, being erupted onto the surface cools quickly, resulting in small crystals. Magma which cools underground can take hundreds of thousands of years to cool, and therefore the mineral crystals grow larger.
Wiki User
∙ 12y agoVisible crystal grains: If you can see the crystal grains that make up the igneous rock, then it has cooled slowly from magma below the surface of the Earth, where mineral crystals have had sufficient time to grow before the magma solidifies.
Non-visible crystal grains: The magma or lava has cooled relatively quickly after eruption on the surface of the Earth, leaving little time for large crystal growth.
Wiki User
∙ 13y agoIt depends on the rate of cooling, you see if the rock cools down slowly then you will have large crystals but if it cools quickly you get small crystals
Wiki User
∙ 10y agoHeating
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Does grain size mean anything when identifying igneous rocks?
yes, it does. when a grain size in an igneous rock is small, it means that it was probably an extrusive rock, meaning it formed on land. but if the grain size is big, it means that the rock most likely formed underground, or it was intrusive. try remembering it like this- the larger the crystals, the more time the rock had to form, and magma cools faster on land, not giving the rocks much time to form.
Is conglomerate intrusive or extrusive?
Neither. Conglomerate is a sedimentary rock. Intrusive and extrusive are descriptive terms used to classify igneous rocks.
In which direction do you sand wood?
never sand wood across the grain always sand with the grain
Why is the surface of smooth sanded birch plywood cabinet doors rough after being painted with semi gloss paint?
The paint raises the grain of the wood. To avoid this: # moisten the surface with water. # allow to dry and thus raise the grain. # resand the wood using a fine grain sandpaper (220 grit). # repeat if the tightness of the grain is especially loose.
What are 3 ways farmers could use pottery?
Way back in the day before grain bins, silos or anything like that ever existed, large pots were needed to store the grain that grain producers harvested. Thus, clay pottery was needed to store grain, and even meats that were salted for preservation.
What is a factor that controls grain size in igneos rocks?
Crystal size in igneous rocks is controlled by the rate of cooling whereby the slower the rate, the larger the size of crystal.
Type of crystal grain that form when molten rock cools quickly?
Small crystal grains form when molten rock cools quickly. In an extrusive igneous rock, it's referred to as aphanitic texture.
Type or crystal grain that form when molten rock cools quickly?
Fine crystal grain.
What effect does a fast cooling rate have on grain size in igenous rocks?
Fast cooling lava or magma creates an aphanitic or small crystal (grain) textured igneous rock.
What type of crystal grain is formed when molten rock cools slowly?
Large crystals with a coarse crystal grain texture.
What grain type is found in extrusive igneous rocks?
Extrusive igneous rocks are usually fine grained.
What texture does and extrusive igneous rock have?
fined grain texture
What is grain according to geologists?
Grain refers to particle or crystal size in rock.
What do extrusive igneous rocks look like?
The particle size (grain size--crystal size) in igneous rock is largely dependent on the amount of time spent cooling and solidifying from molten rock. If cooled quickly, crystals will have little time to grow. Slow cooling allows time for larger crystal growth.
What crystal or grain is granite made from?
marble
Are igneous rocks strong?
Igneous rocks can be strong due to their interlocking grain textures
What does it mean for an igneous rock to have fine grain?
it means unfoliated that's my answer
