Metamorphic rocks with a non-foliated texture show changes that involve recrystallization and the growth of new minerals, but without the alignment of minerals into a layered or banded structure. Here's a breakdown:

Recrystallization:

* What happens: Existing minerals within the rock are broken down and rearranged into larger, more stable crystals. This occurs due to the heat and pressure of metamorphism.

* Result: The rock's overall composition may change, but it doesn't necessarily develop a layered appearance.

Growth of New Minerals:

* What happens: The heat and pressure of metamorphism can create conditions that favor the formation of new minerals. These minerals are usually more stable under the new conditions.

* Result: The rock's composition changes, often becoming more coarse-grained as larger crystals grow.

Absence of Foliation:

* Why it happens: Non-foliated rocks are typically formed under conditions of equal pressure in all directions (confining pressure). This pressure doesn't encourage the minerals to align in a particular direction.

* Result: The rock maintains a relatively homogeneous appearance, without the layering characteristic of foliated metamorphic rocks.

Examples of Non-Foliated Metamorphic Rocks:

* Marble: Formed from limestone, with visible crystals of calcite.

* Quartzite: Formed from sandstone, composed mainly of quartz.

* Hornfels: Formed by contact metamorphism, where the rock is baked by the heat from a nearby magma intrusion.

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