Obsidian Tools and Weapons

Okay, first things first, I have attempted to make this as something that's not "lol betterz than diamondz" as well as I can by providing drawbacks as well as advantages.

Info
Short and simple, Obsidian tools are like a fusion of the durability of diamonds and the mining ability of stone tools. Obsidian pickaxes are able to mine Coal, Iron, and Redstone, but not Gold or Diamond. (It might not make a ton of sense, but it has to be this way for the sake of balance.) Obsidian tools last longer than Diamond tools, however Obsidian pickaxes, axes, and shovels each mine thier own respective blocks about the same speed as stone tools, and Obsidian swords do about the same amount of damage as stone tools. As well, Obsidian swords have a slight chance of lighting the struck mob on fire.

Pros:

 * Extreme Durability
 * Chance of Fire Attack

Cons

 * Limited Amount of Mineable Ores
 * Less Damage/Speed than Iron and Diamond Tools.