A specific Triple Goddess symbol which is non-lunar (i.e. without moon-phase shapes) -- three skirted raised-arms silhouettes (partly derived from PD image File:Spiral Goddess symbol neo-pagan.svg) surrounded by emanating rays.  One reason for a Triple Goddess symbol not based on moon-phase shapes, is that to some degree in Robert Graves' writings -- and very definitely in recent neopagan symbolism -- the moon phases are associated with the stages of a woman's life (maiden, mother, and crone).  A non-lunar symbol would be compatible with many other interpretations also (such as the women associated with the stages of a man's life -- "mother, bride, and layer-out" -- the seasons of the year; the goddesses of the heavens, earth, and underworld; the goddesses of land, air, and sea; etc etc).
Own work based on PD image File:Spiral Goddess symbol neo-pagan.svg and partly vaguely influenced by Minoan/Cretan skirted figurines (see File:Simplified-stylized Minoan snake goddess symbol.svg).
AnonMoos