So in case you haven't found it, I will tell you where it is. First you must make sure that no one in your team gets marked by an oracle during the templar fight. Next you need to ensure that nobody is seen whilst navigating the gorgon's maze. Must be done in a fresh game, not an oracle save-point. At the start of the jumping puzzle, turn left and head through the cave. Drop down carefully and on your left is a little cave with a chest containing a "glass shard." You can receive one "glass shard" for normal and one for hard per character. You can then get a piece of armour from Xur for 1 glass shard or a weapon for 2. Remember where you heard it and teach everyone. You'll know that you've done it right because there will be a heck of a lot more magic platforms that will be spawning in right around the corner. So it is effectively a guaranteed exotic weapon or 2 exotic armours..... Enjoy guys :) Only a few elite clans know of this and few of them care to share!!