Material

NetHack allows each item to be of one material.

When creating wiki articles about materials, consider including things such as:
 * What are examples of items made from that material?
 * What is good and bad about this material?
 * Does it rust, corrode, burn, rot?
 * Does the material behave as one would expect?
 * Was it a good or bad idea to put this material in the game?

List of all materials
Materials as listed in objclass.h: