we are a Chinese trade company,and have done foreign trade for about 20 years,since a long time,we have had lots of customers all over the world,and kept a great relationship,welcome to contact us,if necessary,we are always trying our best to offer the best products and best service.I hope we could bring much more wealth to you. product: potassium feldspar chemical composition: K2O 10.8-11.2% Na2O 3.6-3.7% Fe2O3 Max 0.35% usage: accessorial mineral for make glass or porcelain