Definition:phantasma (fan'-tas-mah) Abstract Noun, Neuter - a Phantom, an apparition, a spirit, a ghost, a friendly or evil spirit.
Diagram: By convention, the sign of an abstract noun is an equilateral triangle.
A "phantom" however could either be a clean (holy) spirit or an unclean spirit. Therefore, the Sign of a "phantom" could either be a white or a dark equilateral triangle.