In this paper,infrared spectroscopic analysis,microscope and electron microprobe analysis were employed to study petrological and mineralogical characteristics of stony appearance portion in placer nephrite.The results show that stony appearance portion in placer nephrite mainly consists mainly of tremolite phenocryst and diopside with minor muscovite. According to the difference of mineral composition of stony appearance portion in placer nephrite, the stony appearance portion in placer nephrite can be divided into tremolite-type, tremolite-diopside type and diopside type. The development of stony appearance portion is related to the grain size and structure of minerals.