Traits Atlas

Codebook, Minimums, Exceptions

Verdigris Patina

Summary: Vivid green-to-teal patina formed by long-term oxidation of copper; valued for painterly variation.

Color: A corrosion patina dominated by copper acetates/carbonates manifesting as green, blue-green, teal deposits or films. On CENTS, it often pools in low-relief areas and along lettering.

Chemistry: Typical compounds include copper(II) acetate and basic copper carbonates (malachite/azurite family).

Cent #2389 – Verdigris notable threshold — Cent #2389 – Notable verdigris (minimum)

Cent #3272 – Significant verdigris — Cent #3272 – Significant

Cent #3981 – Verdigris full — Cent #3981 – Full verdigris

Verdigris Tonings

Cent #1047 – Verdigris silver-grey — Cent #1047 – Silver-grey

Cent #5127 – Verdigris greenish — Cent #5127 – Greenish

Cent #8641 – Verdigris bluish — Cent #8641 – Bluish

Intensity Scale

Notable verdigris: Localised but clearly visible patches or films, typically emerging in multiple zones; roughly from the minimum threshold up to ~20–30% of the face area.
Significant verdigris: Verdigris is a major visual actor with strong presence, but not yet fully dominant; approximately ~30–70% coverage or a smaller area with exceptional chromatic intensity.
Full verdigris: Verdigris is the dominant surface condition, forming continuous regions that visually define the coin; generally > ~70% coverage with a clear green/blue-green read at first glance.

Version 1.1 – updated to notable / significant / full scale