Shiny Baubles are white-yellowish beads found in Labyrinth dungeon chests. They cannot be crafted, and their purpose is to make potion that will make you shine, like a glowstone.
They are added by the Project Zulu mod. In the newest version of Project Zulu, they appear to serve a purpose in crafting potions, but it is unknown whether or not they serve the same purpose in Hexxit, but it looks like it has.
Shiny Bauble about to be used.