No. Intrusive rocks have larger crystals because of the increased time that the magma had available to cool. Elements necessary for mineral crystal growth can migrate more freely and thus form larger crystals during an extended fluid phase.
by the size of the crystals, big crystals intrusive, small crystals extrusive
Intrusive rock normally has visible crystals. Extrusive igneous rock has small crystals. A black extrusive igneous rock with small crystals could be basalt.
Intrusive Rocks are found underneath Earths crust, while Extrusive rocks are found above Earths crust.
Intrusive rock cools slowly beneath the Earth's surface, allowing larger mineral crystals to form, making the rock harder. Extrusive rock cools quickly on the Earth's surface, leading to smaller crystals and a softer composition.
Large crystals are typically characteristic of intrusive igneous rocks, which form beneath the Earth's surface from slow cooling of magma. Extrusive igneous rocks cool quickly at or near the Earth's surface, resulting in smaller crystals or glassy textures.
instrusive Rock
Because as an intrusive rock cools underground, it will normally cool more slowly than an extrusive (surface) rock. The slow cooling allows more time for the crystals to grow.
The two main types of igneous rock are intrusive and extrusive. Intrusive rocks form underground and have larger crystals due to slower cooling. Extrusive rocks form on the Earth's surface and have smaller crystals due to rapid cooling.
== Grain size. Most intrusive igneous rocks will have visible crystals. Crystals in most extrusive igneous rocks are not easily visible.
Two types of igneous rock are intrusive (also called plutonic) and extrusive. There is also porphyry rock which is partly intrusive and partly extrusive. Porphyry rock has large crystals embedded in a mass of much smaller crystals. The large crystals formed underground as does intrusive rock, and were carried in lava when it erupted. The mass of smaller crystals formed around the large crystals when the lava cooled quickly above ground, as does extrusive rock.
D. where the rock was formed determines whether igneous rock is intrusive or extrusive. Intrusive igneous rocks form from magma that cools slowly beneath the Earth's surface, allowing larger crystals to develop. In contrast, extrusive igneous rocks form from lava that cools quickly on the surface, resulting in smaller crystals. Thus, the location of formation is key to classifying igneous rocks.
If a rock has large crystals, it is an intrusive rock. Intrusive rocks form underneath the Earth's surface. Magma cools slowly so it has time to form large crystals. An example is granite, where you can see the crystals with your naked eye. Rocks that have small crystals are extrusive rocks. Extrusive rocks are ones that form from lava (blasted out of a volcano) so they cool very quickly, not allowing large crystals to form. An example is obsidian, where you cannot visibly see the small crystals; it just looks like one black, glassy rock.