Crystalline.
The crystal structure at the center of the lab was stable, yet it would grow over time to take up more of the space. What would happen when it filled all of it? It was needed to keep the environment stable on the planet. Would the foliage survive? If the plants grew larger, could they control the crystals?
Zentangle drawn on Strathmore Vellum Bristol using a black, Micron pen. Shading done with graphite pencil.