I realize this thread is old and threadsurrecting sucks sometimes.
But I was under the impression, and still am under the impression because this is always the way it's been, that crystalline swords can only be found from unlocked chests. I've had them drop from FoW quest chests (the one after wailing lord), these always appear to be purple, and I've had white ones drop from the bugged barrel that used to be in Sanctum Cay, and the chests that used to be part of the riverside mission that dropped everything from ecto's to crystallines.
My question is.... did something change recently among patches, or nightfall release, or something that I missed? I put up my crystalline auction on the auction pages and it only sold for something like 230k. it was gold 15-22req 12, 19% while hexed, 20/20 sundering, and +30hp. IT was from an HoH chest drop a long time ago, almost a year ago. About halfway through the auction, I went from the only person with a sword in the category, to 20 people selling crystallines.
Where did they all come from? Were people just waiting to sell them, or are they becoming more of a common drop now? I'm just confused why an elemental sword which can be easily found in less than a week of searching or trading for cheap and then upgraded with inscriptions (which no crystalline has an upgradable inscription), and added mods can sell for so much and then my crystalline sell for so little when it's way rarer. Any insight?
And a purple ritualist's tunic is something a krytan enemy would drop. White Mantle Ritualist ring a bell?

These other bugged chests like in Sanctum Cay would drop items (I can't remember any names) of enemies that aren't even in the game.
edit:
One of the runs in fissure we did, showing some good drops from the wailing lord quest and the reason why I never miss it anymore. Ecto from the banshees, 2 shards, and a crystalline sword from the chest (which was purple, before coloring in the text took place)