Teton-Black (180 MESH) Foundry Green Sand Olivine Facing Sand for Metal Casting (10LB) Size: 10LB Use for making metal casting molds for a variety of metals ranging from Pewter to Cast Iron Easy to (re)use, simply add water to maintain moisture Ultra-fine formulation--Premium 180 Mesh Olivine (Magnesium Iron Silciate) Raw Sand and Bentonite Blend Professionally Formulated, Pre-Mulled, and Quality Inspected (100% ready to use) More stable, better finish, safer, and longer life than competing silica sands