Hafnon is a hafnium mineral, chemical formula (Hf,Zr)SiO 4 or (Hf,Zr,Th,U,Y)SiO 4. ZrSiO 4 part of the zirconium is replaced by the very similar hafnium and so natural zircon is never pure ZrSiO 4. A zircon with 100% hafnium substitution can be made synthetically and is hafnon.
Hafnon occurs as transparent red to red orange tetragonal crystals with a hardness of 7.5.
Hafnon occurs naturally in tantalum pegmatites and in weathered pegmatites at Mount Holland, Western Australia It has also been reported from locations in Ontario , Canada; North Carolina , United States; and in Zimbabwe