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

Question

Lia Hammond

Biology

29 January, 20:58

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

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Answers (2)

Know the Answer?

Hanna Bender · Answer 1

hey you!

Explanation:

Quartzite

Quartzite is a metamorphic rock formed when quartz-rich sandstone or chert has been exposed to high temperatures and pressures. Such conditions fuse the quartz grains together forming a dense, hard, equigranular rock. The name quartzite implies not only a high degree of induration (hardness), but also a high quartz content. Quartzite generally comprises greater than 90% percent quartz, and some examples, containing up to 99% quartz, and are the largest and purest concentrations of silica in the Earth's crust. Although a quartz-rich sandstone can look similar to quartzite, a fresh broken surface of quartzite will show breakage across quartz grains, whereas the sandstone will break around quartz grains. Quartzite also tends to have a sugary appearance and glassy lustre. The variety of colours displayed by quartzite are a consequence of minor amounts of impurities being incorporated with the quartz during metamorphism. Although quartzite can sometimes appear superficially similar to marble, a piece of quartzite will not be able to be scratched by a metal blade, and quartzite will not fizz on contact with dilute hydrochloric acid.

Texture - granular.

Grain size - medium grained; can see interlocking quartz crystals with the naked eye.

Hardness - hard.

Colour - variable - pure quartzite is white but quartzite exists in a wide variety of colours.

Mineralogy - quartz.

Other features - generally gritty to touch.

Uses - pure quartzite is a source of silica for metallurgical purposes, and for the manufacture of brick; as aggregate in the construction and roading industries; as armour rock for sea walls; dimension stone for building facings, paving etc.

New Zealand occurrences - northwest Nelson (Aorere).

Gregory Woodward · Answer 2

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.