You'll have to explain to me Adamantine sometime, wha's so dangerous about it?
Well for starters Adamantine is by far the strongest metal in DF. It has a damage/protection multiplier of loving 500. You compare that to the next best metal, steel with a multiplier of 133, and you start to get the picture on just how insane this stuff is. Another huge advantage is that it weighs almost nothing, so dwarfs equiped with adamantine stuff won't be bogged down at all.
Adamantine can be used to make any type of furniture/armor/weapon/clothing in the game, except beds oddly. The best use for adamantine, by far, is in making artifacts.
It does come with a teeny tiny problem though, and here I spoiler:
Where there's adamantine, there are Demon Pits nearby. If you aren't careful and you start mining a big juicy vein of adamantine, you'll probably end up breaking into the pit chambers, where a horde of 15-20 invisible demons residing in the pit chambers will immediately swarm out the opening once they discover it and murder the entire fortress. Once the demons start attacking, they'll reveal themselves, other then that there is no way of knowing what you're dealing with after breaking into the pits. Although it is by far the most epic encounter in the game, it can absolutely destroy even a well prepared fortress, which is why it's a cause of concern whenever adamantine is discovered, as to what exactly to do with it. But it's like I said, this only happens when you aren't careful of where you mine.
On another note, the adamantine danger area was only directly South/East of the main shaft. Everything else to the North was perfectly safe rock.
Edit: What Monty said V V V
