This ultra-premium procedural marble material delivers the breathtaking luxury of genuine Italian Nero Portoro, recognized globally as the "King of Marbles." Engineered for elite architectural visualization, the shader features a vast, abyssal black base intersected by sweeping, continuous tectonic rivers of vibrant gold and pristine white calcite. Fully non-repeating to eliminate tiling artifacts across massive surfaces, the material includes three geologically accurate presets—Classico, Macchia Larga, and the ultra-rare Extra / Scuro—granting precise control over vein density, directional stretch, and pooling. Complete with a flawless, glass-like showroom mirror polish and subtle bump mapping that keeps the golden chains realistically flush with the stone, this asset is the definitive choice for dramatic feature walls, prestigious flooring, and the absolute highest tier of digital interior design.