Rare materials

What are some of the rare materials used for, like charcoal, ink vial, and so on. I know ecto and shards are used. But some of these other stuff I find with crafters I just don't understand what they are there for.

Some are used for different armors for different classes. Some are used as ingredients to make other rare materials. Some are just plain useless.

There r material crafters that can make say iron+charcoal (random guess) into steel, i think thats wat ther used for.