In solution, the salt dissociates to give the ferrioxalate anion, [Fe(C2O4)3]3−, which appears fluorescent green in color.

In accordance with the IUPAC convention, the isomer with the left-handed screw axis is assigned the Greek symbol Λ (lambda).

[6] The ferrioxalate anion is sensitive to light and to high-energy electromagnetic radiation, including X-rays and gamma rays.

The potassium salt was found to be over 1000 times more sensitive than uranyl oxalate, the compound previously used for these purposes.

[7][8] The synthesis and thermal decomposition of potassium ferrioxalate is a popular exercise for high school, college or undergraduate university students, since it involves the chemistry of transition metal complexes, visually observable photochemistry, and thermogravimetry.

[9] Before the ready availability of wide ink-jet and laser printers, large-size engineering drawings were commonly reproduced by the cyanotype method.