The Mystery of Fulcanelli’s Violet Iron

In Les Demeures Philosophales, Fulcanelli asserts that alchemically pure iron displays a violet metallic luster. This statement immediately led us to question the conventional understanding of iron’s electronic structure. The standard configuration, [Ar] 3d⁶ 4s², does not permit d → s electron transitions, which are essential for color to emerge in metals. With only greyish metallic reflection possible under such a configuration, we began searching for alternative states that could explain Fulcanelli’s claim.

This inquiry led us to the concept of spin bonds - an arrangement in which atoms remain electrically neutral while adopting non-traditional configurations, such as 3d⁷ 4s¹ and 3d⁶ 4s¹ 4p¹. These states open the door to both d → s and s → p transitions, and more importantly, allow for the energy gap between these orbitals to fall within the visible spectrum. Such a shift is the key condition for a metal to exhibit color.

Through this discovery, we propose that Fulcanelli’s violet iron is not merely symbolic, but a real material whose unique properties arise from an unconventional yet physically plausible electronic structure.