Answer: Crystal
Explanation:
The texture of a rock refers to the size of a crystals, that helps in understanding how a rock formed and how the crystallization of magma has taken place. The texture of an igneous rock depends upon the following factors, such as-
- Cooling rate of magma
- Type of magma and its viscosity
- Crystallization order of different minerals
Some of the types of igneous textures are as follows-
- Aphanitic texture- Here the crystals are too small to be seen with naked eye. It often forms when lava cools rapidly after eruption. Example, basalt.
- Phaneritic texture- Here, the crystals are large enough and easily distinguishable, formed under the earth's surface. Example, granite.
- Porphyritic texture- Here, larger crystals are embedded in the middle of smaller crystals or matrix. Example, porphyry-granite.
- Pegmatitic texture- Here, the rock contains large and massive crystal. Example, pegmatite.
- Glassy texture- When the rocks are comprised of glassy materials, then it is called glassy or vitreous texture. Example, obsidian.