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does silica cleavage or fracture

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does silica cleavage or fracture
asked Aug 20, 2015 by Blas Mata (120 points)

1 Answer

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You can cleave or fracture any stone. Most silicates are extremely hard and conchoidal fractures occur instead of cleaving, for instance, quartz, chalcedony, chert, flint and agate are all silicates. All are so hard they are usually found with conchoidal fracures,Those fractures which allowed the flint nappers of the stone age to make tools and weapons. The hardness is one of the identifiers of these rocks.
answered Aug 21, 2015 by Weasel (38,360 points)
edited Aug 21, 2015 by Weasel
To clarify, there are some harder stones with cleavage as well, but quartz and other silica minerals lack a cleavage property and will fracture with a conchoidal (i.e. shell-shaped) fracture.