Infinity Stone in a Neon Subway Tunnel

Concept art of a colossal Infinity Stone floating in the middle of a damp, abandoned subway tunnel. The stone glows with a vivid emerald-green energy, its facets refracting reflections from flickering fluorescent tubes. A halo of light and swirling motes surrounds the crystal, creating prismatic rainbows that ripple through the air. The tunnel walls are cracked concrete with peeling paint, rusted metal beams, graffiti, and wet puddles that mirror the glow. Rail tracks run toward a distant vanishing point, the far end dimly lit by bluish-green light. The scene is cinematic and highly detailed, with painterly textures, dust particles, and realistic reflections: wet surfaces, grime, and subtle fog. The mood is awe and mystery, as if a universe-altering artifact has just appeared in a ruined transit system. Optional: for extra drama, a second, fainter Infinity Stone of a different color could hover near the first in the background, but keep the focus on the main stone.