From Halopedia, the Halo wiki
Boson beads, also known as phase pearls, are among the rarest gems known to humans.
Boson beads are known to be created through the plasma bombardment of boson-photon fields, also known as hard-light. Boson beads appear as shimmering spheres that can range in size from that of a pea to a little larger than a human thumb-tip. They can at times appear more liquid than solid, but in the proper light are shown to be solid balls that give off a deep and bright iridescent glow. They are considered extremely valuable. According to Veta Lopis, just one phase pearl would have been enough for her to purchase the Trattoria Georgi.
On April 14, 2553, the planet, Shaps III, was partially glassed by the pirate, Sav Fel, with the CCS-class battlecruiser Pious Inquisitor'. The site struck was home to active Forerunner hard-light structures. When the 717th Xeno-Materials Exploitation Battalion deployed a company to Shaps III a short time later to survey the Line Installation 444-447, it discovered valuable boson beads created by the glassing. On December 12 of that year Office of Naval Intelligence operative Veta Lopis made use of these beads to attempt to bribe Ross Nyeto and Georgi Baklanov in turn as part of an undercover operation on Venezia to make members of the Keepers of the One Freedom seek them out.
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