shist
gneiss
Quartz is a mineral, not a rock that neither does or does not exhibit foliation (a banding, layering, or alignment of minerals that presents itself in some metamorphic rocks). Quartzite, a rock made almost entirely of quartz, is a non-foliated metamorphic rock.
Igneous rock (like pumice) does not normally display banding, layering, or flaky texture. Foliated vs. non-foliated as a descriptive term in rock identification is most often used in reference to metamorphic rock.
Metamorphic rocks are rocks that have their grains arranged in parallel layers or bands. Foliated rocks are formed under great pressure and heat, and when they cool they have a banded grain pattern.
The main way metamorphic rocks are classified is by the presence or absence of foliation. Foliated metamorphic rocks are distinguished by the type of foliation they exhibit. Types of foliation textures, include: slaty, phyllitic, schistose, and gneissi.
No banding or alignment of a metamorphic rock's minerals would be consider non-foliated.
It is not true. Metamorphic rock foliation is displayed as banding or layering due to mineral alignment.
The alignment of large porphyroblasts in a fine-grained matrix results in a porphyritic texture in metamorphic rocks. This texture is commonly seen in rocks that have undergone regional metamorphism, where minerals like garnet or staurolite form large crystals in a finer-grained background.
Foliated rocks have layers in them. We often refer to the layers as Banding.
Non-foliated
gneiss
Gneiss
Gneiss
non-foliated.
Slate is certainly foliated and splits easily along this foliation surface. Gneisses frequently banded and this banding is also a foliation.
Quartz is a mineral, not a rock that neither does or does not exhibit foliation (a banding, layering, or alignment of minerals that presents itself in some metamorphic rocks). Quartzite, a rock made almost entirely of quartz, is a non-foliated metamorphic rock.
Certain metamorphic rocks that do not exhibit foliation (banding, lamellar texture) like quartzite and marble are described as non-foliated.