Electron Spin Resonance (ESR) and 3-dimensional Thermoluminescence (3-D TL) spectra of natural diamond

high temperature-high pressure artificial diamond and high temperature-low pressure chemical vapor deposited (CVD) diamond were determined. The characteristics of spectra have been studied. It is found that isolated nitrogen

nitrogen exchange pair and nitrogen atom pair ( S =1) are main forms of electron spin resonancial nitrogen in natural and high temperature-high pressure artificial diamonds. The spectrum of CVD diamond is smpler

and contains only one peak caused by suspended bond of unsaturated carbon ones. For 3-D TL spectra

natural diamond has two peaks (～370 nm and ～510 nm) in 100-200℃ temperature range

high temperature-high pressure artificial diamond only has ～370 nm peak

and CVD diamond only has ～500 nm peak. These characteristics would be useful for the quality inspection and classification of diamonds

as well as for the study of geologic actions associated with natural diamond.