Why are no periods of history called the Brass Age or the Aluminum Age?

Answer 1

Early in the Bronze Age, there was a period some people call the Copper Age. This was a time when the alloys of copper were undergoing experiment, and when brass and bronze were developed. So a brass age would have been the Copper Age or the Early Bronze Age, and the name was simply not needed. (Besides, how many people know the difference between brass and bronze offhand?)

Aluminum never had an age of its own because it never really dominated a time period. Aluminum has been only recently used, and was not even known to exist as a metal until it was first extracted in the 1820's. For a long time, it was more expensive than gold, and it is said that Emperor Louis Napoleon III liked to show off the fact that he owned a table service with aluminum forks and spoons. It was not commonly seen until the 20th century, just as plastics were being introduced. Even today, aluminum is rather expensive for many projects. Aluminum engine blocks, for example, are less common than iron.