Authentication of two samples of ancient Chinese coins with component element depth analysis by confocal 3D XRF

Highlights: • Identification of ancient Chinese iron coins nondestructive by 3D XRF. • Double Peaks Gaussian curve reveals the existence of corrosion layer. • To help archaeologists familiarize 3D XRF and broaden their research tools. Two samples of ancient Chinese coins were analyzed with a confocal three-dimensional micro-X-ray fluoroscope. The depth distributions of elemental iron (Fe), calcium (Ca) and copper (Cu) were obtained based on this non-destructive measurement method. One coin, named "Chongning Tongbao", was certified as genuine in accordance with the available archaeological data, whereas another coin, named "Zhenglong Yuanbao", was identified as a reproduction.