One of the more mature forms of transapientech, these small objects are one of the densest (information-wise, not necessarily mass-wise) commercially available computronium modules, storing information at a quantum level and processing it at the speed of light. Unlike most such transapientech structures the pearls are baseline friendly, which makes them very popular. The exact origin of their design is not known; though it is known that Siris or Black Calliope were not their original developer. Several high-level minds from TRHN and Keter Dominion have confirmed the design as 'not subverted.'
Solar Dominion, Negentropy Alliance and various other empires have declared them as 'Controlled Technology' due to their capacities.
They are available in various 'weights' (some appear to have a magmatter core and are usually placed on a sturdy diamondoid display-stand, while whose meant to be worn or carried may only have a photonanotech core), customized shapes (spherical, oval, hemispherical, split-oval, lens-shaped, etc.), grades (the highest transapients produce the highest grades), capacities (some are mostly memory modules and others are mostly quantum computers) and sizes (the largest available units are 5 centimetres in diameter). [Note that a top grade unit of this size can contain a backup of a high-singularity Power!] Their actual production costs are relatively cheap, though Siris cheerfully charges whatever the market will bear. Also, while the design has been duplicated several times and the low-grade versions can be mass-produced, the denser high-grade versions are still quite rare due to difficulties in production. These are known to require S5 or greater intellect for process control even though required facilities are relatively small.
They interface with outside world via low-power laser beams most often generated by interface units resembling jewellery setting. They are powered in same way by external radiation. The outer shell is actually a diamondoid interface structure whose thin, multiple layers can give the SPM a lustre and iridescence, as such their name comes from their external appearance which closely resembles those terrestrial gems so valuable in ancient times.
One of the more popular and amusing designs is an ancient-style pearl necklace with tremendous processing power and unassuming external appearance, a veritable magical amulet for lower-tech cultures. Sometimes this has caused surprises when someone putting on an heirloom necklace finds her pimple socket interfacing with the extreme processing power. Sometimes this has even led to involuntary integration, ascensions and permanent symbiotic binds. Although rare, this can involve a mind living in the necklace and an overwrite of the unfortunate individual.