CoinProof Lab

CoinProof Lab is an offline-first authenticity and bullion-value workbench for collectors, junk-silver hunters, flea-market and pawn buyers, and new stackers. One hard question comes before any money changes hands: is this coin real, and what is it actually worth? CoinProof Lab answers it with a guided six-checkpoint test flow that ends in a reasoned verdict, a confidence score and the exact reasoning trail behind it. No account, no ads, no tracking, no billing — everything runs on your device. AUTHENTICITY LAB WIZARD Work six checkpoints in order: eye and engraving read, dimensions, weight versus mint tolerance, magnet behaviour, ring-tone reference, and specific gravity. Each checkpoint returns pass, marginal or fail. The app then produces a final verdict, a confidence percentage and a plain-language trail you can read out to a seller. COIN LIBRARY 120+ seeded specifications — weight, diameter, thickness, edge and reeding type, composition, magnetic flag and mint tolerance band — covering US, UK, Eurozone, Canada, Australia and Mexico series plus bullion. Instant search and filters by country, decade, metal and size. PRECISION MEASUREMENT DECK Weight deviation in grams and grains, mm and inch conversion, expected density computed from composition, specific gravity from dry plus suspended weight, and bullion fineness math for .999, .958, .925, .900 and .800 alloys. FAKE PATTERN DESK 24 documented counterfeit signatures — cast porosity, wrong weight band, magnetic core, drilled-and-filled, plated copper, wrong reeding count, soft rim. Each one includes a vector diagram and the single test that catches it. MELT VALUE SHEET Enter spot price per troy ounce for gold, silver and platinum, then compute melt value per coin and for an entire batch: gross weight, net fine weight, purity, per-gram and per-ounce views, plus a wastage margin toggle. GRADING EYE An interactive Sheldon 1–70 slider with criteria text and wear-point callouts for the Morgan dollar, Walking Liberty half, Lincoln cent and Washington quarter, plus a side-by-side comparison of two grades on the same vector coin. RING REFERENCE BENCH An on-device tone generator plays reference pitches grouped by diameter and metal, so you can compare a suspicious coin's ring by ear. No microphone permission required. CALIBRATION KIT Guided verification of your own scale and caliper against known references — nickel 5.000 g, dime 2.268 g, quarter 5.670 g — with drift guidance, so every downstream verdict stays trustworthy. FIELD KIT AND EXPORT A compact pre-purchase checklist for markets and pawn counters, plus a one-tap share of the finished verdict card as text. VALUE POCKET WIDGET A home-screen widget showing current per-gram melt value with a deep link straight into the Melt Value Sheet, plus an optional weekly reminder to refresh spot prices. Built for people who handle real metal in the real world. Offline-first and private by design.