Where does a particle's magnetism come from? While the Standard Model explains the magnetic dipole moment through the Dirac equation and quantum radiative corrections, this paper presents a deeper, geometric origin derived from the Helix Light Vortex (HLV) theory. It demonstrates that a particle’s magnetic properties are not intrinsic, but emerge from the topology of the vacuum itself — as localized, circulating spiral field currents. The paper derives the g-factor from first principles based on spiral field geometry and quantized resonance modes in a discrete dodecahedral vacuum lattice. This approach not only recovers the known quantum predictions in the low-energy limit but also makes falsifiable predictions for deviations near strong gravitational fields or topological defects in the vacuum. Ultimately, this work replaces an abstract quantum property with a physical, testable mechanism, offering a new fundamental understanding of particle magnetism — grounded in emergent geometry, not imposed symmetry. https://orcid.org/0009-0002-5709-9729