soljille

Soljille is a fictional mineral described in speculative fiction and in some role-playing game settings as a crystal capable of harvesting and storing solar energy for later discharge. In most depictions, soljille forms under intense solar flux in icy or volcanic environments, either naturally within planetary crusts or synthetically in laboratories. The name blends "sol" for sun with an invented suffix, reflecting its solar origins.

Physically, soljille is described as translucent to opaque, with colors ranging from pale yellow to deep amber. Crystals are typically glassy or prismatic, and the material is usually assigned a moderate hardness and a high refractive index. Descriptions of its stability vary, but many sources place it as resistant to ultraviolet radiation while sensitive to moisture and thermal cycling.

In-universe, the energy-storage mechanism of soljille is explained through photochemical lattice structures or quantum-state descriptions, allowing charging under sunlight and on-demand discharge as light, heat, or electricity. Because of its rarity and processing requirements, large-scale use remains limited in most stories, with applications including ship power cores, emergency lighting, and remote power modules.

Culturally, soljille is employed in science fiction literature and games as a plot device to explore renewable energy, resource distribution, and technological ethics. See also fictional energetic materials and auric crystals.