Hafnium Tetrachloride (HfCl₄) is a white to off-white crystalline solid commonly used as a precursor in the production of hafnium metal and hafnium-based compounds. https://www.noahchemicals.com/product/hafnium-iv-chloride-99-95-pure-80-mesh-hafnium-tetrachloride-hfcl%e2%82%84/