Abstract: Based on the observation with optical microscope and analysis by EDS of electron microprobe and scan electron microscope, the scattering particles existing
in lead fluoride crystals were firstly confirmed to be lead metal. Their shapes are characterized by gradually evolving from irregrlar shape to diamond shape. There is a face
which direction is always parallel to the (100) face of PbF₂ crystal. It was suggested that the scattering particles are formed from the following process: reduction
of lead metal, inclusion of melt, nucleation and solidification along some direction of PbF_2 crystal.

Key words: PbF₂ crystal, scattering particle, lead metal