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Glossary · Disclosure

Patina (metal)

The stable corrosion layer on ancient copper alloy — smooth green malachite, blue azurite, red cuprite — built over centuries and legitimately valued.

The stable corrosion layer on ancient copper alloy — smooth green malachite, blue azurite, red cuprite — built over centuries and legitimately valued. A patina that is soft, uniform, or sits in the recesses only is applied; a stripped and repatinated coin is a disclosure.

Sources

Cite this article

Stratum Strata. "Patina (metal)" (Glossary). Stratum Strata pack 2026.09, as of 2026-09-16. https://stratum.black/strata/glossary/patina-metal. Accessed 2026-09-21.

BibTeX · CSL-JSON

@misc{stratum-patina-metal,
  title        = {Patina (metal)},
  author       = {{Stratum Strata}},
  howpublished = {\url{https://stratum.black/strata/glossary/patina-metal}},
  year         = {2026},
  note         = {Glossary article, Stratum Strata pack 2026.09, as of 2026-09-16; sources: stratum. Accessed 2026-09-21.}
}

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