GoWish

I suppose that is possible... But Raboniel seemed to think that white sand was more common-place. Especially seeing as white sand can be reproduced from a seed, and Raboniel seemed to have prior experience with white sand. I would assume that they already had some and could reproduce it. This would effectively make the prospect of more sand not super valuable. Although... I suppose it is possible that she did not have any yet this return. My only other issue (and this one applied to the "chain from the lands of the dead" as well) is that there seemed to be an implication that, whatever the contents of the bag, Raboniel would receive more of it if she followed through with the agreement (I remember it being a down payment of sorts). Thus, it would presumably be something that would continue to be very valuable if she received more of it. As stated before, this would unlikely to apply to white sand. And the aforementioned "chain" seems to be a specific artifact... so having more of those seems unlikely. Hence my theory of it being raysium.

Ah... Interesting... Thank you!

In chapter 60, before Raboniel is presented with the 'gift' of Lift, she is given a pouch with something that clinked (so presumably metal). She seems to think the contents of this pouch are very valuable. Was it ever revealed what the pouch contained? I cannot think of it off the top of my head, but maybe I am forgetting something? My best guess is that it is raysium, but I don't know for sure.