All Earth (Alchemical Substances)

Alchemical substances that traditional sources class under the element Earth, meaning solid, dry and heavy materials of the ground such as sulfur, medicinal clays and special stones. An entry belongs here when the alchemical or pharmacological texts that describe it treat it as an earthy material, whatever its chemical nature. It excludes metals, salts and spirits, which have their own groups. The group page lists these materials together so that a reader can follow how alchemical writers sorted the substances of their craft into natural kinds.