Coin Pinger
Acoustic bullion authentication — free, private, on-device
Coin comparison
British Half Sovereign vs Gold Sovereign
Overlapping rings: how these two gold coins differ on the scale, under the calipers, and — computed from first-principles physics — in the ring.
Official specifications, side by side
| British Half Sovereign | Gold Sovereign | |
|---|---|---|
| Weight | 3.994 g | 7.988 g |
| Diameter | 19.3 mm | 22.05 mm |
| Composition | .9167 gold (22k) | .9167 gold (22k) |
| Mint | The Royal Mint | The Royal Mint |
Expected ring, mode by mode
| Mode | British Half Sovereign | Gold Sovereign |
|---|---|---|
| c0d2 | 4.01–5.05 kHz | 4.93–5.70 kHz |
| c0d3 | 9.33–11.66 kHz | 11.48–13.07 kHz |
| c0d4 | 16.38–20.47 kHz | above 20 kHz |
Their fundamental bands overlap (4.01–5.05 vs 4.93–5.70 kHz), so a single ping may not separate a British Half Sovereign from a Gold Sovereign — combine the ring with the weight and diameter checks, which differ. Frequencies are computed from each coin's published mass, diameter, and metal via free circular-plate physics — see the methodology.
Home · All coins · Calculator · Open data · Algorithm · Methodology · Open source (MIT) · Terms · Privacy