Coin Pinger
Acoustic bullion authentication — free, private, on-device
Authenticity guide
Is my Morgan Dollar real?
Four checks — weight, size, magnet, and the ring — catch the overwhelming majority of fakes, because a counterfeit can fake the look but not the physics. Every threshold below is computed from the official spec and our acoustic model.
The 60-second checklist
| Check | Genuine Morgan Dollar | Red flag |
|---|---|---|
| ⚖ Weight | 26.73 g ±0.3 g (wear trims a little) | More than ±0.3 g off |
| 📏 Diameter | 38.1 mm ±0.1 mm | Visibly off, or fails calipers |
| 📏 Thickness | ≈2.4 mm at the rim | Noticeably thick (hiding low density) |
| 🧲 Magnet | No attraction at all | Any pull = steel core |
| 🔔 Ring (c0d2) | 3.86–4.82 kHz | Any peak outside the bands below |
What fakes sound like — computed, metal by metal
A struck disc's ring is fixed by √(stiffness ÷ density). A genuine Morgan Dollar rings its fundamental at 3.86–4.82 kHz (higher modes: 8.93–11.07 / 15.56–19.29 kHz). Here is where the same-size coin lands in the metals counterfeiters actually use — computed from published elastic constants, no guesswork:
| Struck in… | Fundamental | Weight at right size | What you'd hear |
|---|---|---|---|
| Genuine silver | 3.86–4.82 kHz | 26.73 g | clear, sustained ring |
| copper-nickel (struck fake) | ≈6450 Hz | ≈23.1 g | the most common struck-fake alloy — rings far higher than silver |
| silver-plated copper | ≈5650 Hz | ≈23.2 g | rings higher, decays faster, and comes in underweight |
| silver-plated zinc | ≈6100 Hz | ≈18.5 g | tinny, higher ring and badly underweight |
| steel core | ≈7950 Hz | ≈20.3 g | far higher ring — and the magnet test catches it before you even tap |
| silver-plated lead | ≈1850 Hz | ≈29.3 g | a dull, dead thud that dies instantly |
Plated and base-metal fakes also decay faster — solid precious metal has very low internal damping, so a genuine coin ring lasts; fakes die out. Coin Pinger measures both. Full resonance reference →
Known Morgan Dollar fakes — what's actually out there
The Morgan is the most heavily counterfeited classic US coin — CBP's Chicago mail facility seized 281 shipments of fakes, 95% from China. Common struck fakes use a copper-zinc-nickel body with about 1% silver: the lighter alloy forces a thicker coin, which a scale, calipers, and the ring expose. The deceptive tier is numismatic — altered mintmarks and key-date fabrications (1889-CC, 1893-S, 1895) on genuine silver planchets; NGC even documented an 1895-O with correct weight and composition, caught only by die diagnostics. Be clear-eyed: the ping test authenticates the metal and planchet, not the date or mintmark — key-date premiums need a loupe or professional grading.
Morgan Dollar authenticity — frequently asked
How can I tell if my Morgan Dollar is fake?
Run four checks: weight (genuine: 26.73 g ±0.3 g, a bit less with heavy wear), diameter (38.1 mm ±0.1 mm), the magnet test (genuine silver is not magnetic), and the ring test — a genuine Morgan Dollar's fundamental rings at 3.86–4.82 kHz, and every common fake metal rings measurably elsewhere. Passing all four is strong evidence of authenticity; failing any one is a red flag.
Does a fake Morgan Dollar stick to a magnet?
Only steel-core fakes do — genuine silver is not magnetic, so any magnetic pull means fake. But most fakes (copper-nickel, plated copper) are also non-magnetic, so passing the magnet test proves little on its own. Combine it with weight and the ring.
How much does a fake Morgan Dollar weigh?
A right-size fake in copper-nickel weighs about 23.1 g and in plated zinc about 18.5 g — versus 26.73 g genuine. Counterfeiters must choose: right weight with wrong size, or right size with wrong weight. Calipers plus a scale corner them; the ring test catches what both miss.
Can a counterfeit Morgan Dollar pass the ping test?
A wrong-metal fake cannot — the ring is set by √(stiffness ÷ density), and no common fake metal matches silver's. The hardest case is a genuine-alloy counterfeit struck to correct specs; those are rare and expensive to make, and against them the ping test is one strong signal among several — combine it with weight, dimensions, and a trusted seller.