We have determined that good single crystals of iron(II) iodide (FeI2) UP to 60 mm in area are obtained under highly restrictive initial conditions. These conditions include the high temperature end of the vapor reaction ampoule being between 550 to 575-degrees-C with an initial argon pressure of 0.6 to 1 mTorr. Previous optical data and theoretically predicted X-ray spectra are confirmed.