Here's why:
* Foliation is the development of layers or bands in metamorphic rocks due to the alignment of minerals under pressure. This is common in rocks that experience directed pressure, like those found near tectonic plate boundaries.
* Nonfoliated metamorphic rocks form under conditions of uniform pressure, without a specific direction of force. This prevents the minerals from aligning in a layered pattern.
Examples of nonfoliated metamorphic rocks include:
* Marble: Formed from limestone.
* Quartzite: Formed from sandstone.
* Hornfels: Formed by contact metamorphism (heat from magma).
* Anthracite: Formed from coal under high pressure and heat.
