MintMark Atlas

MintMark Atlas is an offline studio for identifying mystery coins from physical measurements and mint marks. It is for hobby numismatists, coin-club newcomers, estate-sale browsers, youth collectors, and antique-mall scavengers who want a fast shortlist before they buy, trade, or set a piece aside. Start with the live spec matcher. Enter diameter, weight, thickness, and edge type, then filter by metal family. Lock a candidate series, pin where the mint mark sits and which style it uses, and narrow a seed catalog of common circulating and classic series to plausible candidates. Each series card shows the portrait, reverse motif, years, and diameter and weight baselines. The mint-mark atlas includes position diagrams for the obverse and reverse, style variants, and era notes for major series. Variety compare mode places two candidates side by side and highlights design differences: legends, devices, date styles, and privy marks, with clear callout chips. Study the Sheldon grade ladder from Good through Mint State using visual wear checkpoints. It builds grade literacy and does not assign a grade for you. The edge encyclopedia covers reeded, plain, lettered, decorated, and security edges with tactile cue notes. A composition quick reference lists alloy families, specific gravity hints, and common look-alike traps. Pin 1 to 12 matches for each mystery coin, add private notes, and mark a candidate ruled out or still open. Share a plain-text summary of the key specs and shortlist. Practice recognition with a mint-mark quiz that shuffles mark tiles, tracks a score streak, and reviews the marks you missed. MintMark Atlas works fully offline, with no accounts and no cloud library. It is not a collection journal, a craft canvas, or a photo identifier. Use it as a field guide, and confirm rare or high-value coins against a specialist reference.