Question

which sentence best describes an igneous rock with pegmatitic texture?
it has especially large crystal grains.
it has no visible crystal grains.
it has large, layered crystal grains.
it has very fine, randomly distributed grains.

Explanation:

Pegmatitic texture in igneous rocks is characterized by extremely large crystal grains. This occurs due to slow cooling of magma in a relatively undisturbed environment, allowing ample time for mineral crystals to grow. The other options are incorrect: rocks with no visible crystal grains are typically glassy (like obsidian), layered crystal grains are not a defining feature of pegmatitic texture, and very fine - grained rocks usually form from rapid cooling (like basalt from lava flows).

Answer:

It has especially large crystal grains.