size: 325mesh,400mesh,600mesh whiteness:75-80%,above 90% Hardness:3-3.5 usage: oil drilling paiting Filling of plastic Typical Properties of Physical and ChemicalSpecific Gravity4.3~4.4Ba(Sr)SO497-98%Size325mesh,400mesh,500mesh,600mesh,800mesh,SiO20.5% maxOil Absorption7~10 Brightness (Hunter L)92minAl2O30.1% maxPh Value6~9CaO0.3% maxMoisture0.1% maxHg1ppm maxLoss on Ignition1% maxCd