This spell transforms your body into living iron, which grants you several powerful resistances and abilities. You gain damage reduction 15/adamantine. You are immune to blindness, critical hits, ability score damage, deafness, disease, drowning, electricity, poison, stunning, and all spells or attacks that affect your physiology or respiration, because you have no physiology or respiration while this spell is in effect. You take only half damage from acid and fire. However, you also become vulnerable to all special attacks that affect iron golems.
You gain a +6 enhancement bonus to your Strength score, but you take a -6 penalty to Dexterity as well (to a minimum Dexterity score of 1), and your speed is reduced to half normal. You have an arcane spell failure chance of 35% and a -6 armor check penalty, just as if you were clad in full plate armor. You cannot drink (and thus can't use potions) or play wind instruments.
Your unarmed attack deals damage equal to a club sized for you (1d4 for Small characters or 1d6 for Medium characters), and you are considered armed when making unarmed attacks.
Your weight increases by a factor of 10, causing you to sink in water like a stone. However, you could survive the lack of air at the bottom of the ocean--at least until the spell duration expires.