Signalstone

Signalstone is a term used in speculative fiction and theoretical materials science to describe a gemstone-like object capable of encoding, storing, and relaying information through physical signals. In many fictional contexts, signalstones are passive transceivers that can be written with data and then transmit it over distances without sustained power.

Composition and mechanism: Signalstones are described as crystalline or amorphous solids with designed dopants or photonic structures. Information is embedded by applying a resonant energy pulse that alters the stone's internal state, and it is read by a compatible reader tuned to the stone's resonance. Some variants harvest ambient energy to reemit signals, enabling intermittent or continuous output.

Capabilities and uses: They can receive, store, and re-emit signals, acting as data capsules, beacons, or routing nodes in a network. They support time-delayed messaging and can secure communications when paired with cryptographic readers. Practical limitations include range, environmental interference, material fatigue, and the need for compatible hardware for writing and reading data.

History and usage: The concept appears across science fiction and fantasy, with roots in legends of luminous stones that carry messages. In such settings, artisans and engineers craft signalstones of varying sizes and dopants to suit tasks from personal communication to planetary-scale networks.

Real-world context: There is no established material known as a signalstone in real science; the term is used primarily in fiction and speculative discussions as a hypothetical or imagined technology.