Theory
When Reiji's bracelet, Aila's necklace, and the chairman's pocket watch glow they all coincidentally have the same green gems.
And as Nil stated the glow increased the plavsky particles, implying some sort of relation between them.
The other two jewlery also hints that more of these green gems exist and can also be found on Earth.
This also explain how to chairman knew about Reiji and Aria.
I also believe the chairman called the gem the Arista
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