The method uses spontaneously emitted gamma-rays from a radioisotope source, typically cadmium-109 at 88 keV or cobalt-57 at 122 keV. Detectors employed are typically NaI(Tl) or HPGe. After a two-part gamma-ray split, detection pulses are windowed for the characteristic pulse amplitude and measured in coincidence. By using high resolution detectors and gamma-ray frequencies whereby the detector has a high photoelectric effect efficiency, coincidence rates are found to substantially exceed the chance rate, in defiance of quantum mechanics. This unquantum effect implies that photons are an illusion, and is explained by an extension of the long abandoned loading theory of Planck. In scattering gamma-rays in beam-split geometry, changes in response to magnetic fields, temperature, and crystal orientation become tools to measure properties of atomic bonds in the beam-splitter material. With detectors in tandem geometry where the first detector is both scatterer and absorber, tests reveal properties consistent with a classical gamma-ray model. The unquantum effect has also shown sensitivity to the crystalline state of the source material. Conventional gamma-ray spectroscopy shows no substantial response to these applied variables.