Mary the Jewess is believed to have lived sometime during this broad period. The lack of concrete evidence makes pinpointing a specific birth year impossible. Her existence and contributions are primarily based on citations and descriptions within the works of later alchemists, primarily Zosimos of Panopolis, who wrote several centuries after her time. The uncertainty surrounding her exact lifespan adds to the aura of mystery surrounding this foundational figure in alchemy.

Mary is credited with the invention or significant improvement of several crucial alchemical apparatuses. These inventions are instrumental to early alchemical processes. While the precise details of their original forms are debated, their impact on the evolution of laboratory techniques is undeniable. She is considered a pioneer in what would evolve to become laboratory methodologies.