This is an amber colored, cage filament, tipped Edison Mazda light bulb. This bulb is extremely hard to find. I've only seen 2 other bulbs like this one listed on eBay, one of which sold for $78 USD in January 2003. Mine cost $42.51 plus shipping in Feb-2004. 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. I believe the light given off by these amber bulbs might've been considered to be too similar to the transparent types, so maybe not many of these bulbs were sold and perhaps that is why they are so rare. They are made of true colored glass (not painted). The color is actually called "natural amber".

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 metal 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.