... 1.made from natural high quality crystal stone 2.high content of SiO2 3.low impurity Quartz sand (powder) is mainly applied ... treatment filtration, exact foundry, refractory, ceramic, casting, printing, dyeing, quartz melting, petroleum, chemical, abrasive, etc, Silicon content is very high ... for the 10ppm maximum.we can supply different sizes quartz grain,welcome to contact us for the further details. ...