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Gold Panda 30 g — ping test & specs

The Gold Panda is China's official gold bullion coin; since 2016 the main coin is 30 g .9999 (earlier issues were 1 troy oz). Its purity and size set its ring.

Opens the free tester with this coin preselected — audio never leaves your device.

Official specifications

Weight30 g
Diameter32 mm
Thickness2.7 mm
Composition.9999 fine gold

Source: China Gold Coin Corporation. Coin Pinger checks measured weight and diameter against these values.

Expected resonance range

Provisional confidence*
ModeExpected ringRecommended variance
c0d23.45–4.13 kHz±9.1%
c0d37.99–9.48 kHz±8.5%
c0d413.92–16.50 kHz±8.5%

A genuine Gold Panda 30 g 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 provisional-confidence tag reflects how well-established this metal's constants are: Computed from .9999 gold's annealed modulus — the least-certain material input, so the band is widened and this reference is best confirmed by calibrating a coin you know is genuine. 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.

* These are computed guidance ranges. Certain your Gold Panda 30 g is genuine but it won't match? Send us its ring — we'll dig in and improve the reference.

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How to ping test a Gold Panda 30 g

  1. 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.
  2. Tap — strike the edge with a striker near the microphone.
  3. Read the verdict — MATCH or NO MATCH against the peaks above, plus weight and size checks.

Gold Panda 30 g — frequently asked

How much does a Gold Panda 30 g weigh?

The official specification is 30 g in .9999 fine gold (source: China Gold Coin Corporation). Coin Pinger's weight check allows ±0.3 g by default.

What size is a Gold Panda 30 g?

32 mm in diameter and 2.7 mm thick at the rim, per China Gold Coin Corporation. 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 Panda 30 g ring at?

Its fundamental (c0d2) vibration mode is computed to ring in the 3.45–4.13 kHz range, with higher modes near 7.99–9.48 kHz and 13.92–16.50 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 Panda 30 g 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 Panda 30 g in the app.

Does ping testing damage a Gold Panda 30 g?

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.

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The physics of the Gold Panda 30 g ping

Those 3 peaks aren't random. When you strike the coin it flexes as a free disc in fixed patterns called vibration modes — 0 nodal circles with 2, 3 and 4 nodal diameters, written c0d2 / c0d3 / c0d4. Each pattern rings at one frequency.

Where those frequencies land is set by the coin's geometry and metal. For a thin disc, frequency ∝ (thickness ÷ diameter²) × √(stiffness ÷ density). This Gold Panda 30 g spreads 30 g of .9999 fine gold across 32 mm — an effective disc thickness of about 1.9 mm once the raised rim and relief are averaged out — which puts its fundamental (c0d2) near 3790 Hz.

An ideal thin disc's modes sit at fixed, geometry-only ratios: 1 : 2.33 : 4.11. A real coin isn't infinitely thin — shear in the metal drags the higher modes slightly below the ideal — so this coin's computed reference lands at 1 : 2.30 : 4.01. Spacing near those ratios is the fingerprint of a struck disc, and Coin Pinger rejects taps that don't fit it (keys, glass, a coin lying on a hard surface).

And it's why a fake can't hide: change the metal and √(E/ρ) changes, so every mode moves. Struck in tungsten (which weighs almost exactly right) instead, the ring would land far higher and brighter — its c0d2 would land near ≈9050 Hz instead of 3790 Hz. Density can fool a scale; the ring can't be faked without the right metal.

We publish this as a Provisional confidence reference. Computed from .9999 gold's annealed modulus — the least-certain material input, so the band is widened and this reference is best confirmed by calibrating a coin you know is genuine.

Free-plate modes per A. W. Leissa, Vibration of Plates, NASA SP-160 (1969, public domain). See how we measure them →