Aurora and Northstar's Master Edition Handbook profiles...both say Durability: Enhanced Human...

http://www.unfluffybunny.com/cripp12...auroraback.jpg

http://www.unfluffybunny.com/cripp12...thstarback.jpg

Granted, this is before they were altered by Weapon X and the Hand respectively. However...I've seen/read nothing that suggests Aurora's skin is any harder than Northstar's.

Dana