Coin Pinger
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Gold coin guide
Gold Krugerrand 1/4 oz — ping test & specs
The quarter-ounce Krugerrand is a 22.06 mm 22k gold coin. At this size two vibration modes remain within phone-mic range.
Opens the free tester with this coin preselected — audio never leaves your device.
Official specifications
| Weight | 8.482 g |
| Diameter | 22.06 mm |
| Composition | .9167 gold (22k) |
Source: Rand Refinery / South African Mint. Coin Pinger checks measured weight and diameter against these values.
Expected resonance range
Good confidence*| Mode | Expected ring | Recommended variance |
|---|---|---|
| c0d2 | 5.23–6.04 kHz | ±7.2% |
| c0d3 | 12.15–13.85 kHz | ±6.5% |
A genuine Gold Krugerrand 1/4 oz rings within these ranges at its c0d2/c0d3 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 good-confidence tag reflects how well-established this metal's constants are: Computed from 22k-gold alloy constants, which are slightly less certain than silver; the band is set accordingly. 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.
Small-coin note: at 22.06 mm this coin is below the ≥25 mm sweet spot — its ring is higher-pitched, shorter, and quieter than a full-size coin's, and only two of its modes stay under the 20 kHz phone-mic ceiling. Tap close to the microphone in a quiet room, expect more retries, and lean harder on the weight and diameter checks.
* These are computed guidance ranges. Certain your Gold Krugerrand 1/4 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 Gold Krugerrand 1/4 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.
Gold Krugerrand 1/4 oz — frequently asked
How much does a Gold Krugerrand 1/4 oz weigh?
The official specification is 8.482 g in .9167 gold (22k) (source: Rand Refinery / South African Mint). Coin Pinger's weight check allows ±0.3 g by default.
What size is a Gold Krugerrand 1/4 oz?
22.06 mm in diameter, per Rand Refinery / South African 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 Gold Krugerrand 1/4 oz ring at?
Its fundamental (c0d2) vibration mode is computed to ring in the 5.23–6.04 kHz range, with higher modes near 12.15–13.85 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 Gold Krugerrand 1/4 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 Gold Krugerrand 1/4 oz in the app.
Does ping testing damage a Gold Krugerrand 1/4 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.