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Silver Lunar Series III 2 oz — ping test & specs

The 2 oz Lunar III is the largest coin we reference: 62.2 g across 50.8 mm. Big and broad, it rings low with all three modes cleanly readable.

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

Official specifications

Weight62.213 g
Diameter50.8 mm
Composition.9999 fine silver

Source: Perth Mint. Coin Pinger checks measured weight and diameter against these values.

Expected resonance range

High confidence*
ModeExpected ringRecommended variance
c0d22.80–3.33 kHz±8.5%
c0d36.52–7.63 kHz±7.9%
c0d411.36–13.31 kHz±7.9%

A genuine Silver Lunar Series III 2 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). This coin's band is widened further because the issue is struck at slightly varying thickness across years. 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.

* These are computed guidance ranges. Certain your Silver Lunar Series III 2 oz 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 Silver Lunar Series III 2 oz

  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.

Silver Lunar Series III 2 oz — frequently asked

How much does a Silver Lunar Series III 2 oz weigh?

The official specification is 62.213 g in .9999 fine silver (source: Perth Mint). Coin Pinger's weight check allows ±0.3 g by default.

What size is a Silver Lunar Series III 2 oz?

50.8 mm in diameter, per Perth 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 Lunar Series III 2 oz ring at?

Its fundamental (c0d2) vibration mode is computed to ring in the 2.80–3.33 kHz range, with higher modes near 6.52–7.63 kHz and 11.36–13.31 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 Lunar Series III 2 oz ring slightly off the listed frequencies?

The Silver Lunar Series III 2 oz is struck at slightly varying thickness across years, and frequency scales directly with thickness — so genuine specimens from different years ring at measurably different pitches. Phone-mic capture adds a few percent more tap-to-tap spread. That's why this reference band is wider than average.

Does ping testing damage a Silver Lunar Series III 2 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.

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The physics of the Silver Lunar Series III 2 oz 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 Silver Lunar Series III 2 oz spreads 62.213 g of .9999 fine silver across 50.8 mm — an effective disc thickness of about 2.9 mm once the raised rim and relief are averaged out — which puts its fundamental (c0d2) near 3065 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 : 2.31 : 4.02. 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 lead or a plated base metal instead, the ring would land far lower and die out with a dull, short thud — its c0d2 would land near ≈1350 Hz instead of 3065 Hz. Density can fool a scale; the ring can't be faked without the right metal.

We publish this as a High confidence reference. Computed from well-established silver elastic constants and cross-checked against same-size sibling coins.

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