Abstract:The barytocelestine is one of the main gangue minerals in the molybdenum deposit of Huanglung Pu area. The veins of molybdenite-galena-pyrite-barytoce- lestine-quartz-calcite occur as large veins or network veins in spilite of the Xionger grup of Sinian Suberathem. The mineral is sallow, cream yellow and milky white in colour, and greasy in lustery usually 4 × 1.2-3 × 2.5cm in size, it has a platy form and sometimes with beaded shell-layer structure on its crystal faces. Specific gravities and hardness determined of two samples are 4.06 and 4.13 and 157kg/mm2(3.6) and 159kg/mm2(3.7) respectively.The mineral is optically biaxial positive with 2v= 61-630; (001)cleavage perfect; firstorder yellow interf erence colour s parallel- axial extinction; positive or negative elongations and Ng=1.637, Nm = 1.629 Np=1 .627,Ng-Np=O.OlO.It has been found that barytocelestine is often replaced by calcite. The unit-cell dimensions of two samples are as follows, a=8.472, 8.509, b=5.381, 5.408;c=6.927, 6.958A;v=315.80, 320.19A3;z=4. The strongest lines in the x-ray powder pattern are 3.465 ( 4.5),3.325(10),3.210(6),2.998(7.5), 2.755(4.7),2.691(4),2.065(6),2.032(4). The calculated molecular formula of barytocelestine is(Sro.59 Bao.34 Ca0.04)SO4. The weathered product of the barytocelestine shows a white or yellowish white colour and has a mesh structure. It is identical with baryte.