Coin Pinger
Acoustic bullion authentication — free, private, on-device
Silver coin guide
Silver Britannia 1 oz — ping test & specs
The Silver Britannia is The Royal Mint's flagship 1 oz silver bullion coin, .999 fine since 2013 (earlier issues were .958 Britannia silver at 40 mm). Its size and purity set its resonance.
Opens the free tester with this coin preselected — audio never leaves your device.
Official specifications
| Weight | 31.21 g |
| Diameter | 38.61 mm |
| Thickness | 3 mm |
| Composition | .999 fine silver (2013+) |
Source: The Royal Mint. Coin Pinger checks measured weight and diameter against these values.
Expected resonance range
High confidence*| Mode | Expected ring | Recommended variance |
|---|---|---|
| c0d2 | 4.31–4.91 kHz | ±6.5% |
| c0d3 | 10.00–11.21 kHz | ±5.7% |
| c0d4 | 17.37–19.47 kHz | ±5.7% |
A genuine Silver Britannia 1 oz rings within these ranges at its c0d2/c0d3/c0d4 vibration modes, fixed by its size and metal. The recommended variance is how far a genuine specimen's ring can sit from each center — built up in quadrature from real manufacturing tolerance and temperature (under 1%), phone-mic capture reproducibility (≈4%), an extra allowance on the fundamental for minting-asymmetry splitting, and a per-metal model-uncertainty term (largest for .9999 gold, whose modulus is least certain). The higher modes also carry a small thick-plate centre correction, since a real coin is not infinitely thin. The high-confidence tag reflects how well-established this metal's constants are: Computed from well-established silver elastic constants and cross-checked against same-size sibling coins. These are guidance bands, not exact values — see the methodology for the exact formula, or calibrate your own coin in the app for a specimen-exact reference and tighten each peak per coin.
Worried yours might be counterfeit? How to spot a fake Silver Britannia 1 oz →
* These are computed guidance ranges. Certain your Silver Britannia 1 oz is genuine but it won't match? Send us its ring — we'll dig in and improve the reference.
🎙 Submit sample pingsHow to ping test a Silver Britannia 1 oz
- Hold — grip the coin by its center (a nodal point) in a coin ping-test holder so the rim rings freely; a fingertip at the center is a last resort.
- Tap — strike the edge with a striker near the microphone.
- Read the verdict — MATCH or NO MATCH against the peaks above, plus weight and size checks.
Silver Britannia 1 oz — frequently asked
How much does a Silver Britannia 1 oz weigh?
The official specification is 31.21 g in .999 fine silver (2013+) (source: The Royal Mint). Coin Pinger's weight check allows ±0.3 g by default.
What size is a Silver Britannia 1 oz?
38.61 mm in diameter and 3 mm thick at the rim, per The Royal Mint. Note the average disc thickness is less than the rim caliper reading — the raised rim and relief concentrate metal at the edge.
What frequency does a genuine Silver Britannia 1 oz ring at?
Its fundamental (c0d2) vibration mode is computed to ring in the 4.31–4.91 kHz range, with higher modes near 10.00–11.21 kHz and 17.37–19.47 kHz. These are first-principles physics computations from the coin's published mass, diameter, and metal — not measurements of sample coins.
Why does my genuine Silver Britannia 1 oz ring slightly off the listed frequencies?
Phone-mic capture moves a genuine peak a few percent tap-to-tap — strike point, holding pressure, and the microphone's own response all matter. Temperature and normal minting tolerance add under 1%. The published band already allows for all of this; for a tighter reference, calibrate your own genuine Silver Britannia 1 oz in the app.
Does ping testing damage a Silver Britannia 1 oz?
No — the test needs only a light tap on the edge with a non-marring striker (a wooden pencil or plastic stylus works well), far gentler than normal handling. Hold the coin at its center so the rim can ring freely.