Foliated Rocks:

* Slate: Fine-grained, smooth, and easily split into thin sheets. Formed from shale or mudstone. Used for roofing, flooring, and blackboards.

* Phyllite: Has a silky sheen and a slightly wavy surface. Forms from slate with increased metamorphic grade.

* Schist: Coarse-grained, with visible mineral crystals. Can have a variety of colors depending on the minerals present. Used for decorative purposes.

* Gneiss: Banded appearance with alternating layers of light and dark minerals. Formed at high temperatures and pressures. Used as building stone.

Non-Foliated Rocks:

* Marble: Metamorphosed limestone, often white but can have a variety of colors depending on impurities. Used for sculptures, building materials, and decorative purposes.

* Quartzite: Metamorphosed sandstone, hard and durable, with a sugary texture. Used for building materials, countertops, and decorative purposes.

* Anthracite: A hard, black, and lustrous coal formed from bituminous coal under extreme pressure and heat. Used as fuel and for manufacturing coke.

* Hornfels: A dense, hard, and fine-grained rock formed by contact metamorphism. Often has a glassy appearance.

Difference between Foliated and Non-Foliated Metamorphic Rocks:

The primary difference between foliated and non-foliated metamorphic rocks lies in their texture:

Foliated rocks: Exhibit a layered or banded appearance due to the alignment of minerals during metamorphism. This alignment is caused by directed pressure, which forces minerals to elongate and flatten in a specific direction.

Non-foliated rocks: Do not exhibit a layered or banded appearance. This is because they were formed under equal pressure from all sides, or the minerals within the rock were not easily deformed.

Here's a table summarizing the key differences:

| Feature | Foliated Rocks | Non-Foliated Rocks |

|----------------|----------------|--------------------|

| Texture | Layered, banded | Non-layered, uniform |

| Mineral Alignment | Aligned in a specific direction | Randomly oriented |

| Pressure | Directed pressure | Equal pressure from all sides |

| Examples | Slate, phyllite, schist, gneiss | Marble, quartzite, hornfels |

Understanding the differences between foliated and non-foliated metamorphic rocks helps us to interpret the history of the rocks and the conditions under which they formed.