Luxury Diamond Jewelry Mockup

Generate a hyper-realistic image of a large, round brilliant cut diamond resting on a black velvet surface, with a spotlight shining down from above, creating a dramatic highlight on the diamond's facets and a subtle glow on the surrounding fabric, against a dark gray gradient background that fades to black at the edges, with the diamond positioned centrally and its reflection visible on the velvet surface, capturing the intricate details of the diamond's cut and the soft, luxurious texture of the fabric, in a style reminiscent of high-end jewelry advertising, with precise lighting, natural shadows, and detailed textures, without any watermarks or logos. The image should convey a sense of luxury, sophistication, and elegance, highlighting the diamond's exceptional quality and craftsmanship. The overall mood should be dramatic and opulent, with the spotlight drawing attention to the diamond's brilliance and fire. The image should be rendered in a highly detailed and realistic style, with accurate mockup construction and refined styling. The color palette should feature a predominantly dark gray and black scheme, with the diamond's facets sparkling white and the velvet surface exhibiting a subtle sheen. The image should be free of distractions, with the diamond and its reflection remaining the sole focus of the composition.