A hyper-realistic 3D image of a crystalline glass skull, intricately detailed and illuminated from within by pulsating blue light, casting ethereal shadows and reflections. The skull's transparency is accentuated by subtle gradients of sapphire and azure hues, enhancing the glowing effect. It is suspended against a deep, velvet-black background, with iridescent specks resembling distant stars. Rendered using the Octane engine, the image exudes a mysterious and futuristic atmosphere, with hints of spectral purple tints intermingling with the blue, creating an otherworldly and enigmatic ambiance.