Sharing content derived from non-OGL sources

[Angafirith]

I was thinking about creating some Augment Crystals and posting them here on these forums. The concept of Augment Crystals is introduced and explained in the Magic Item Compendium, which is not OGL content.

Is it legal for me to post any crystals I create? I should be fine as long as I don't post one directly out of the book, right?

EDIT: Realized I gave it a nonsensical title.

[Fax Celestis]

Yes. As long as you don't describe the mechanical process of the items, and don't copy/paste existing items, there's no reason you can't make some.