In this manuscript, we reveal some insights into the nucleation and growth mechanism of pure silica zeolite HPM-1. This chiral material has attracted interest from academic and industrial researchers due to its potential for application in asymmetric catalysis and the separation of racemic products. We investigate four samples synthesized with different crystallization times and characterize them by X-ray diffraction, infrared spectroscopy, electron microscopy and small-angle X-ray scattering (SAXS). We propose a four-step synthesis mechanism based on the different populations of nanoparticles and the porous surface intermediate that is observed. We demonstrate that this synthesis follows a nonclassical mechanism of zeolitic nucleation and growth.