The texture thus described is referred to as aphanitic texture.
Igneous rocks can contain both small and large crystals, depending on how quickly they cooled from molten material. If they cooled slowly beneath the Earth's surface, they tend to form large crystals, as seen in rocks like granite. Conversely, if they cooled rapidly on the surface, such as in volcanic eruptions, they typically have small crystals or a glassy texture, as seen in rocks like basalt.
The texture depends on the size and shape of the crystals you see in it. The larger the crystals, the slower the rate of cooling. This suggests that it is an intrusive rock. Smaller crystals suggest more rapid cooling indicating that it is an extrusive rock. INTRUSIVE- cooled inside the earth and had more time to create crystals EXTRUSIVE- cooled on the surface of the earth and created small crystals
Extrusive Igneous rock cools quickly above ground so it has a smooth texture so there isn't enough time for crystals to form and intrusive igneous rock forms inside a volcano or other underground hot place and takes longer to cool so crystals can form. It is extrusive.
Igneous rocks that cool slowly have larger crystals because there is more time for the crystals to grow and develop before the rock solidifies. In contrast, rocks that cool quickly have smaller crystals due to limited time for crystal growth during the rapid cooling process.
Granite, diorite, and gabbro are examples of igneous rocks that do not have a glassy texture. These rocks are formed from slowly cooled magma underground, allowing time for crystals to grow, giving them a coarse-grained appearance.
Igneous rocks that cooled slowly are intrusive. Igneous rocks that cooled quickly are extrusive. Intrusive rocks form larger crystals, because the crystals have a longer time to grow. Extrusive rocks have small to no crystals, because they had little or no time to grow/form.
Andesite is an Igneous Rock. It has small crystals because it cooled quickly d;D
The texture depends on the size and shape of the crystals you see in it. The larger the crystals, the slower the rate of cooling. This suggests that it is an intrusive rock. Smaller crystals suggest more rapid cooling indicating that it is an extrusive rock. INTRUSIVE- cooled inside the earth and had more time to create crystals EXTRUSIVE- cooled on the surface of the earth and created small crystals
The main difference is that the glassy textured igneous rock cooled from lava with extreme quickness, while the one with a fine texture cooled less quickly. Obsidian is a natural glass, created by rapidly cooling lava, where mineral crystals do not have enough time to form before the lava solidifies.
If lava cools quickly, the minerals don't have as much time to form crystals, so the crystals do not become very large. Igneous rocks that cooled quickly and have small crystals are described as "aphanitic" igneous rocks.
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).
The crystals within don't have as much time to grow when igneous rock is cooled more quickly as in extrusive igneous formation.
the rate melted rock cools.
Extrusive Igneous rock cools quickly above ground so it has a smooth texture so there isn't enough time for crystals to form and intrusive igneous rock forms inside a volcano or other underground hot place and takes longer to cool so crystals can form. It is extrusive.
Obsidian rocks are cooled very fast, and you cannot see the crystals in them.
Igneous rocks that cool slowly have larger crystals because there is more time for the crystals to grow and develop before the rock solidifies. In contrast, rocks that cool quickly have smaller crystals due to limited time for crystal growth during the rapid cooling process.
An igneous rock with a glassy texture cooled from its' liquid state very quickly, an example of this would be obsidian, a volcanic glass.