This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
A periodic element entry records one of the chemical elements of the periodic table specifically for its place in the history of alchemy and esoteric thought, rather than as a chemistry reference does. Before the modern periodic table existed, the same substances now called elements, mercury, sulfur, gold, lead among them, carried symbolic and spiritual meanings within alchemical traditions that treated the work of refining a physical substance as inseparable from the refining of the soul that performed it.
Each entry records an element's alchemical symbol where a distinct one exists, since alchemical texts used a specialized graphic notation rather than the modern letter based symbols chemistry now uses, along with any planetary correspondence assigned to it, since Western alchemy traditionally paired specific metals with specific planets, gold with the sun and silver with the moon among the clearest examples.
The entry also records an element's place in the modern periodic table itself, its atomic number and its natural abundance, since a full picture of what a substance meant to an alchemical tradition requires knowing what it actually is chemically as well as what earlier practitioners, working without that knowledge, believed it to be and why they believed it.