Convincing evidences are obtained, that glory in classic definition is formed in clouds of negative temperature as a rainbow of first order on spherical particles with a refractive index of 1.81-1.82 and the diameter greater than 20 μm. It is proved that glory on a cold cloud is the rainbow formed on spheres with the aforementioned optical properties. New confirmation is obtained of the earlier found existence of liquid water droplets in especial state of amorphous water, or A-water, in cold clouds. The visible size of glory can be an indicator if the maximum size of the A-water droplets, and its additional rings can mean the presence of some shapes of ice crystals.