good quality,best price,prompt delivery Commodity:Potassium rich FeldsparSpec/analysis; Form: Lump, grains or powderSize: 0-8mm, ... .0-19.0%Fe2O3: <0.15%====================================Potassium rich feldspar is silicate mineral with rich potassium, characterizes low melting point, long melting time ... glaze, abrasives, milling tools and materials,welding rod etc. 325mesh potassium feldspar lump