A Philoopher's Stone is the chosen technology of the Aquarius.
A Philosopher’s Stone is a computer-like device encased in a lead pendant that hangs from a silver chain around their neck. It's design varies according to which of the six Clans the Aquarian belongs to.
It is used to access holographic data or send messages to others. Clans are connected through a network of Philosopher’s Stones so that at any given moment, an Aquarian can access every member of her Clan at once, transmitting a video feed of what she’s seeing and opening a channel to her Elders’ counsel.