Create a high-resolution illustration of a [skull] icon in the style of a glossy, translucent sculpture. The icon should appear as if made of curved, flowing glass with reflective surfaces. Infuse the form with vivid, refracted rainbow gradients that shift smoothly across its contours. The shape should be abstract yet recognizable, with a sleek, high-gloss finish and soft reflections that mimic light bending through clear material. Center the icon on a solid black background. No shadows, textures, or extra elements. Square aspect ratio.