Guild Wars 2

I am confused right now~ The recipe I bought from the guild hall (Guild insignia) so that I can craft an ornate armor.

So the problem is, on the description of the insignia, I can use shimmering crystal or tenebrous crystal. But Instead of shimmering crystal, I need to use the tenebrous crystal only, the description says ‘OR’?
Did I miss something here?

Please Help,
Cheers

You can use either 10 of the shimmering crystals or 10 tenebrous crystals. You only need 10 of 1 kind to craft it. See my guide on dulfy for more info.
http://dulfy.net/2015/12/24/gw2-hot-guild-armor-and-weapons-guide/