User blog comment:Fairy Tail Grand Master/What is the hidden blade made of?/@comment-4862210-20120627211714/@comment-5240355-20120630072311

Naruto 713 gave me an idea; when they questioned an Apple Reference... I mean, who knows? Maybe there's been some fidgeting with it? Altair used the Apple to make the blade not require the sacrifice of a finger, maybe he also made it stronger? Maybe that was an unforseen side effect? Perhaps it showed him where to find metal stronger than what everyone else was using?

... It would be iteresting if it were Diamond, but not likely. At all. XD

But there has to be history somewhere about what everyone's armour was made of... If we knew that, we could figure out what would be stronger than all of them..