The alembic comes to mind: from the Arabic al-anbiq, the word has its roots in the Greek ambix which is of even more ancient origins, perhaps Hebrew. Ambix means cup, used by alchemists to distil potions and elixirs. I see it as a symbol for the transmutation from the unreal to the real through the distillation of an admixture of experience and ideas. Another circle turned on the axis of the idea of the vessel. (See previous post, Conversation, intersubjectivity and the Suspension of Reality.)