The item in wits bag

[Passion]

There is a scene from when shallan is in Kholinar      Where she discovers wit is there and he tells the story of nomon. In that scene we see the following sequence. In middle of storytelling wit glances back at his bag and shallan observed that he is surprised by something and no one else seems to notice. No immediate explanation is forth coming. Shortly afterwards he glances at her and shallan feels recognized even though she is posing as veil. At the very end of the scene shallan is talking to wit and catches a glimpse inside his pack and sees an object that is mostly black with a small amount of white facing up.

so what happened here? Apparently we are supposed to conclude it was this object that helped him identify her. Do we know anything about what it is or how it works? Also I couldn’t help but wonder if it actually fully identified her as she seemed to think he recognized her or if perhaps it only told him she was wielding radiant power and that was what surprised him?

Thanks in advance for helping me figure this out

[CrazyRioter]

The object in question is a bottle of the sand found on Taldain (from White Sand). The sand contains a microrganism that reacts to use of Investiture nearby, turning the usually dark sand white.

[+hwiles]

Darn! I really wanted to jump in with an "obviously it's one of the seals on the Dark One's prison" and score some easy Memory of Light points, but this seems pretty open-and-shut...

[Ripheus23]

8 hours ago, hwiles said:

Darn! I really wanted to jump in with an "obviously it's one of the seals on the Dark One's prison" and score some easy Memory of Light points, but this seems pretty open-and-shut...

Luckily, the Stormlight Archive is the seal on the Wheel of Time, so your theory has merit.