Lesson 2.5: Metamorphic Rocks Study Guide
Like raw dough becoming cookies in the oven, rocks can change form due to heat and/or pressure.
Key Idea: Any rock that forms from another rock as a result of heat or pressure (or both) is a metamorphic rock.
Heat and/or pressure can change:
 Shape
 Texture
 Composition
The change can be:

Igneous to Metamorphic

Sedimentary to Metamorphic
 Metamorphic to Metamorphic
Heat or pressure can increase from:
Magma Pockets Plate Collisions Depth
Key Idea: Geologists classify metamorphic rocks according to the arrangement of the
grains making up the rock.
Foliated-thin, flat layering in most metamorphic rocks
Nonfoliated- grains are arranged randomly (not layered)
Key Idea: The metamorphic rocks marble and slate are important materials for building and sculpture.
Marble is used for statues and buildings.
 Many colors
 Even grain

Can be cut into thin slabs
Slate is used for roofing, outdoor walkways, and trim for buildings.

Many colors
 Foliated-splits easily into flat pieces

Lesson 2.5: Metamorphic Rocks

Can be carved into many shapes
Study Guide