We can supply all kinds of Magnesium sulphate and have exported it for many years ,
1) heptahydrate 98%,99% fertilizer grade / industry grade 
white crystal powder Mg: 9.5% min Sulphur: 12.5% min Chloride:0.014% max Fe: 0.003% max As: 0.0004% max Heavy metal: 0.001% max
2) heptahydrate 99.5% min pharmaceutical grade (BP USP) Size: 0.1-1/ 0.2-3/ 1-4 mm MgO: 16.27% min Mg: 9.8% min Fe: 0.001% max As: 0.0002% max Heavy metal: 0.001% /0.0004%/0.0008% max Insoluble matter in water: 0.01% /0.001% max PH: 6-8
3) monohydrate 98% min Size: 0.1 mm MgO: 27% min Mg: 17% min Fe: 0.0015% max As: 0.0002% max Heavy metal: 0.0008% max Insoluble matter in water: 0.01% max PH: 6-8
4) anhydrous 98% min Size: 0.1 mm MgO: 32% min Mg: 19% min Fe: 0.0015% max As: 0.0002% max Heavy metal: 0.0008% max Insoluble matter in water: 0.01% max
We also supply Magnesium sulphate 2H2O /3H2O , if you are interested in our product pls contact with me directly

Major Products and Services:Caustic Soda Flakes, Pearls and Solid