Mechanics before appearance
Start with the U.S. Mint’s production sequence. Ask where the proposed feature could form and what secondary evidence that event should create. An off-center strike, for example, should affect both faces and preserve an unstruck area. A misaligned die normally affects one face while the other remains centered.
Metal-flow evidence
Strike pressure moves metal. Genuine clips, broadstrikes, indents, brockages, folds and multiple strikes often show predictable flow, weakness, flattening order, collar interaction, or design continuity. Cutting and squeezing after the mint create different surfaces.
Measurements and composition
Wrong-planchet and missing-layer claims require calibrated weight, dimensions, edge evidence and often non-destructive composition testing. Color is insufficient.
Die-repeatability evidence
Doubled dies, RPMs, clashes, cuds and die chips repeat on coins from the same die. Known markers and die-state progression matter more than a single zoomed letter.
Holder and certificate verification
Verify certification numbers on the grading service’s official website and match the coin, label, grade and attribution. A real certification number copied onto a counterfeit holder does not authenticate the object in front of you.