This sentence appears to be describing a type of material, likely a form of stone such as marble or granite, characterized by a deep grey color with distinctive and prominent pale vein patterns. These vein patterns add a reflective, shiny quality to the surface, making it visually striking and potentially beautiful for use in various applications, such as countertops, flooring, or wall cladding in both residential and commercial environments. The description emphasizes the intensity and depth of the grey color, suggesting a sense of richness and sophistication.