The official GemStone IV encyclopedia.
Pure professions refer to those professions that have access to three spell circles and who are expected to train in Spell Research at least twice per level, and lores once per level.
These professions are physically weak, generally unable to wear heavy armor, but they have a vast arsenal of magic to aid them in their work. The pure professions of GemStone are:
A pure is officially defined as a profession with access to a profession base spell circle and two additional spell circles.
Each of the four pure professions has access to Alchemy through its guild skills.