Gold's identification with the Sun is the single most stable and universal correspondence in the whole planetary metal scheme, attested across the Hellenistic, Islamic, and European alchemical traditions with essentially no recorded dissent; Lawrence Principe and other historians of alchemy treat the seven metal, seven planet pairing as one of the oldest and most consistently held frameworks in the entire discipline. Gold's alchemical symbol, a circle with a central dot, doubles as the Sun's own astronomical and astrological glyph, a direct visual expression of the correspondence rather than an arbitrary shared shape.
What gold's central role in alchemy leaves unresolved, and what this atlas keeps carefully separate as its own entry, is the philosophers' stone, the hypothetical agent of transmutation that alchemical tradition hoped could turn base metal into gold; gold itself is not that agent, but rather the goal, and no historical account describes gold as anything other than perfectly ordinary elemental gold once obtained, whatever process was believed capable of producing it from lesser metal. Modern nuclear physics can, technically, transmute other elements into gold inside a particle accelerator, but only in quantities and at costs that make the feat a scientific curiosity rather than anything resembling the alchemical promise of turning lead into gold at practical scale.