A new electronic mechanism for diamond crystallogenesis is proposed that considers diamond synthesis at the microscale (atomic and subatomic levels) rather than in terms of the traditional macroscale conditions of high pressure and temperature (P-T). This challenges the traditional understanding of diamond formation and demonstrates for the first time that the fundamental Coulomb interaction is involved in the synthesis process. The law of diamond crystallogenesis is derived from this synthesis mechanism. This law states that the rate of diamond growth is determined by the number of electrons involved and the oxidation state of carbon. Pressure and temperature play a supporting role and serve as triggers that initiate the electronic mechanism of diamond synthesis. This law suggests that electrons act as crucial catalysts, facilitating the transition of carbon to the C-4 state, where it can form the diamond lattice through the Coulomb interaction, which is much stronger than the forces achieved by pressure. Electrons play a fundamental role in modifying the reactivity of carbon and a key role in the formation of covalent bonds. The law is mathematically expressed using fundamental constants. The discovery of the law of diamond crystallogenesis dispels the myth of millions and billions of years required for diamond formation, as well as the myth of pressure and temperature as direct factors in diamond formation. The law of diamond crystallogenesis and the electron mechanism of diamond crystallogenesis point to the reality of ultra-fast diamond synthesis at atmospheric pressure and low temperatures.