Certificate of authenticity (COA)

A dealer's signed statement of what a specimen is, where it is from, and what has been done to it, with a photograph. Only as good as the dealer's knowledge and honesty; the record behind it is what matters, and a verifiable certificate (Stratum's signed COA) lets a buyer check it.

Sources

Cite this article

Stratum Study. "Certificate of authenticity (COA)" (Glossary). Stratum Study pack 2026.09, as of 2026-09-16. https://stratum.black/study/glossary/coa. Accessed 2026-09-20.

BibTeX · CSL-JSON

@misc{stratum-coa,
  title        = {Certificate of authenticity (COA)},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/glossary/coa}},
  year         = {2026},
  note         = {Glossary article, Stratum Study pack 2026.09, as of 2026-09-16; sources: stratum. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.