Metamorphic Rocks
Non-Foliated Rocks
| Amphibolite | |
| Texture: | Medium to coarse grained |
| Degree of Metamorphism: | Low |
| Protolith: | Mafic or ultramafic igneous rocks |
| Minerals present: | Amphibole, biotite, feldspar, talc |
| Comments: | - abundant chunky amphiboles |
| Hornfels | |
| Texture: | Fine grained |
| Degree of Metamorphism: | Low to high |
| Protolith: | Any rock type |
| Minerals present: | None visible, but silicates |
| Comments: | - Gray, green, black - Looks like a basalt, but “rings” |
| Marble | |
| Texture: | Fine to coarse grained |
| Degree of Metamorphism: | Low to high |
| Protolith: | Limestone or dolostone |
| Minerals present: | Calcite or dolomite |
| Comments: | - Coarse, crystalline - Usually white to grey, but can also be pink, green, etc. - May have veins or fossils (low grade only) |
| Quartzite | |
| Texture: | Fine to coarse grained |
| Degree of Metamorphism: | Low to high |
| Protolith: | Sandstones |
| Minerals present: | Quartz |
| Comments: | - Looks like a quartz sandstone, but grains are fused together - Usually white - Fused quartz grains means that a crack will propagate straight through the grains as they all have the same amount of strength; in a sandstone, the crack will go around the grains as the grains are stronger than the matrix. |