Radiolaria is the leftover remnants of the creature the vex came from; it is the mucus of transitioning from carbon based to silicon/whatever based life form. Flesh and bone gets converted to radiolaria in the process of becoming a vex from a guardian, elinski, etc. Ikora is stupid though. She is highly opinionated and usually wrong. Go through the story of D2 again, listen to how much trash she talks about Osiris ... when he was always right and doing the right thing for survival of the system; and she never apologizes for it. Ikora and the fat headed titan are terrible people and terrible decision makers ... well, zavala is just stupid. He told us to forget about the traveler when we start the campaign and everyone loses their light. He wants to destroy the ship siphoning off the sun without thinking about the consequences. Ikora, she is just one of those people who are sure they are right and on the right path and if you question it, you are wrong. Osiris, in forsaken, even if he isn't in the interactable story, is now their best developed character left in the game who isn't a douche or dumb as rocks. Never listen to what those two 'leader' guardians say. Eris Mourn, Cayde-6, Osiris ... the only well rounded developed characters they've made, and none of them are going to be in the game to interact with ... guess I'll have to double down on visiting our little faction guys in EDZ and Io; even though the first is a bit of a troll, the other is a bit grumpy ... and I do like the Bray lady :p Sloane whines about being in a wet environment a bit too much for me and I can't get into her. wait what, we were talking about white juice? yeah, its the snot leftovers of the body converting to a machine. Poor Io guy ...