You are buying 100 grams High Purity Sodium Iodide, USP/ACS grade powder / crystals, 99.9+%. This is the highest quality and purity in USA. Made and packaged in USA. Same day Ship!. Appearance (Color) White Appearance (Form) Powder Assay (as NaI), CAS: 7681-82-5 F.W.: 149.89: Formula: NaI