Roman alum


Definition of Roman alum

: alum crystallized in cubes especially : alum formerly made from alunite at Tolfa near Rome that was reddish because of a very small amount of iron oxide though otherwise very pure

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First Known Use of Roman alum

1653, in the meaning defined above

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The first known use of Roman alum was in 1653

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Cite this Entry

“Roman alum.” Dictionary, Merriam-Webster, Accessed 28 Nov. 2021.

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