What “no indications of heating” actually establishes

A negative laboratory finding means the examination did not detect the specified evidence under its test conditions. It does not, by itself, prove that the event being investigated never occurred.

The difference is explicit in gemstone heating reports. “No indications of heating” describes an examination result. “Never heated” describes the stone’s entire treatment history. The second statement is stronger than the first.

Gemstone reports describe detection

For corundum reports issued by Laboratory Manual Harmonisation Committee member laboratories, the harmonized wording distinguishes no indications of heating from indications of heating. Heating conditions do not leave identical traces in every stone. A treatment that leaves no detectable trace can coexist with an accurate negative examination result.

An inconclusive result is different again. Where observations point toward possible externally sourced diffusion but corroboration is insufficient, the harmonized reporting system provides wording that leaves the question open and identifies the need for further analysis. That result establishes neither confirmed diffusion nor confirmed absence of diffusion.

The useful distinction is between detected evidence, no detected evidence, and evidence insufficient for a determination. Compressing the three into “certified untreated” destroys the distinction the report was written to preserve.

Wine dating has a detection window

Caesium-137 gamma spectrometry provides a different example. Sealed-bottle measurement can examine wine without opening it, but the dating information depends on the isotope’s presence and the reference pattern.

In the studied Portuguese wines, samples around the atmospheric fallout peak separated more clearly than samples outside that period. The reference curve built from the Porto wines showed no detectable activity before 1960 or after 1965, while wines from another region returned measurable activity in years on both sides of that range. A nondetection therefore did not select one unique vintage from those different possible histories, and the detection window itself was not the same for every regional series.

Take a suspect bottle that returns no detectable caesium-137. That finding alone does not establish that its claimed vintage is correct, that it is counterfeit, or that it belongs to a particular earlier period. The result is narrower than each proposed conclusion.

A result needs a target and a method

A laboratory result remains interpretable when it retains the tested property, method, relevant window, and decision category. Non-invasive describes how a sample is examined; it does not describe how much the examination can establish. Negative describes the finding; it does not assign a probability of authenticity.

The same reporting discipline applies to stones and bottles without making their tests equivalent. Each method has its own detection conditions, and each conclusion must remain within them.