Rahu is not a planet but a shadow. It is like floating smoke. His characteristics are Cold prone and Vaat nature. Ravi is the cause of radiance, while Rahu is the cause of darkness. Rahu is the fruit bearer like Saturn. Rahu is the head of the demon and Ketu is the torso. Rahu exerts authority over dark skinned creatures. He shows the properties of both Water elements and Air elements. He exalts in Gemini. Shankar is his deity. Onyx is its gemstone.