This is a cobalt blue, cage filament, tipped Edison Mazda light bulb. The little glass tip on top tells us that this bulb was made before 1922. Bulbs like these were commonly used for theater stage illumination. This bulb is made with true colored glass (not painted).

The filament style present in this bulb is called a "cage filament", and is made of an uncoiled tungsten wire. It is supported by a glass rod with several hooks on it. The usual amount of hooks is 10, but there can be many more, especially in the case of 220 volt bulbs which require a longer tungsten wire. People often find this type of filament hard to describe. It is simply a very long continuous filament, not multiple filaments as most people usually (mistakenly) say.