Vert Moyen Custer feldspar 17 G-200 feldspar 17 Kona F-4 feldspar 17 Nepheline syenite 17 Whiting 20 Silica 12 Total 100 Bentonite 5 Rutile 5 R&B Scale 1 R&B Scale comes from where steel billets are stored before they are hot-milled to become bars, concrete rods,.wires, etc. It was 45-mesh sieved, hence the specks at high concentrations. It is probably mainly made up of Iron Oxides. Chemical Composition of the Base Na2O 0.20 Al2O3 0.42 SiO2 2.94 K2O 0.16 TiO2 0.18 MgO 0.01 Fe2O3 0.01 CaO 0.63 Alumina:Silica ratio is 1.00:7.07 Neutral:Acid ratio is 1.00:7.51 Alk:Neut:Acid ratio is 1.00:0.42:3.12 Expansion: 87.9 x 10e-7 per degree C --------------------------- Vert Moyen Picoté Custer feldspar 17 G-200 feldspar 17 Kona F-4 feldspar