Black Iron Oxide - Fe3O4 - Natural - 5 Pounds Description Shipped in a resealable bag that is sealed for safety and freshness. It includes a tear-off tab for easy opening. Features: Fe3O4, also known as magnetite or Iron (II,III) Oxide This comes from a natural source so the product has slight variation in color Particle size runs about 500 mesh (30 microns) Used in welding, pigments, ceramics, along with a lot of other uses We sell bulk for so many different uses, we don't include any specific use instructions Product Details: Brand: Alpha Chemicals Item Form: Powder Item Weight: 5.1 Pounds Is Discontinued By Manufacturer ‏ : ‎ No Product Dimensions ‏ : ‎ 7 x 4 x 11.5 inches; 5.1 Pounds Date First Available ‏ : ‎ January 23, 2011 Best Sellers Rank: #36,484 in Industrial & Scientific (See Top 100 in Industrial & Scientific) #33 in Analytical Reagents #33 in Analytical Reagents Customer Reviews: 4.5 4.5 out of 5 stars 600 ratings