Which words or phrases describe characteristics of quartzite? Check all that apply.

igneous

non-foliated

metamorphic

does not split into layers

grains arranged in parallel layers

Answer: non-foliated, metamorphic

Explanation:

Unlike quartz, an igneous rock which forms a crystal from magma or as a precipiate near hydrothermal vents, quartzite is formed from applying heat and pressure to sandstone, thus it is metamorphic. The intense conditions during its formation tightly compresses and interwinds the quartz grains, the resulting rock becomes hard and dense. As a non-foliated rock, quartzite does not show repeated parallel bands and it breaks across grains to split into flat layers.