The texture of an igneous rock made up entirely of crystals big enough to be easily seen with the naked eye is phaneritic . Phaneritic texture is sometimes referred to as coarse-grained igneous texture. Granite, the most well known example of an intrusive igneous rock, has a phaneritic texture.
What can you tell about an igneous rock that is coarse-grained?
Igneous rocks are rocks formed from the crystallization of a liquid (molten rock). ... Magmas and their resultant plutonic rock
Which word best describes an igneous rock with large crystals in a coarse-grained texture?
Intrusive best describes an igneous rock with large crystals and a coarse-grained texture.
What do large crystals in an igneous rock tell us?
The size of crystals in an igneous rock is an important indicator of the conditions where the rock formed. An igneous rock with large crystals probably indicates that the rock formed deep within the Earth , since it is typically warmer deep inside the Earth than near the surface.
Which of the following textures describes an igneous rock with anomalously large crystals?
Which of the following textures describes an igneous rock with anomalously large crystals? Pegmatitic
What is the most common type of extrusive rock?
The most common extrusive igneous rock is basalt , a rock that is especially common below the oceans (Figure 4.6). Figure 4.5: Extrusive or volcanic igneous rocks form after lava cools above the surface.
What are the 4 types of igneous rocks?
Igneous rocks can be divided into four categories based on their chemical composition: felsic, intermediate, mafic, and ultramafic .
Why do intrusive igneous rocks have large crystals?
When magma cools within the Earth, the cooling proceeds slowly. Slow cooling allows time for large crystals to form, so intrusive igneous rocks have visible crystals.
What is the name of a very porous igneous rock?
Pumice , a very porous, frothlike volcanic glass that has long been used as an abrasive in cleaning, polishing, and scouring compounds. It is also employed as a lightweight aggregate in precast masonry units, poured concrete, insulation and acoustic tile, and plaster. Pumice. Related Topics: Volcanic glass Extrusive ...
How can you tell if a rock is igneous?
Igneous rocks are very dense and hard. They may have a glassy appearance . Metamorphic rocks may also have a glassy appearance. You can distinguish these from igneous rocks based on the fact that metamorphic rocks tend to be brittle, lightweight, and an opaque black color.
What are the 2 types of igneous rocks?
The two main categories of igneous rocks are extrusive and intrusive . Extrusive rocks are formed on the surface of the Earth from lava, which is magma that has emerged from underground. Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.
What factors influence the texture of an igneous rock?
Texture of igneous rocks defines the shape, size and mutual relationship of the constituent minerals. The texture in igneous rocks depends on the following four factors: i) Viscosity of magma ii) Rate of cooling iii) The order of crystallization of the constituent minerals.
What is the example of extrusive igneous rock?
Types of extrusive igneous rocks include: pumice, obsidian, andesite, rhyolite, and basalt .
What is the rarest type of volcanic rock?
Komatiite is a very rare extrusive igneous rock only formed from incredibly hot magnesium-rich magma. The lava is so hot that it flows like water.
What is the most common type of rock found on the earth’s crust?
The most abundant rocks in the crust are igneous , which are formed by the cooling of magma. Earth’s crust is rich in igneous rocks such as granite and basalt. Metamorphic rocks have undergone drastic changes due to heat and pressure. Slate and marble are familiar metamorphic rocks.
What is the most common type of igneous rock?
One of the most common igneous rocks is granite (Figure 4.1). Granite is used extensively in building materials and making statues. Perhaps you have used a pumice stone to smooth your skin or to do jobs around the house. Pumice is another example of an igneous rock (Figure 4.2).
