Elegant Solitaire Engagement Ring on Calla Lily

Ultra luxury macro jewelry campaign photograph of a solitaire engagement ring: single 2.5ct round brilliant cut diamond, polished 18K white gold, plain ultra slim band (1.8mm wide, 1.7mm thick), elegant four prong setting, no pav, no halo, no side stones, clean polished shank, true to life proportions and realistic diamond scale. Ring rests delicately on the outer petal of a single foreground white calla lily sharply in focus, visually dominant hero subject. Flower is elegant support surface only; ring is not inside the bloom, not around the stem, not mixed with the floral center. Calla lily has silky satin texture, soft ivory white tones, subtle translucency, clean botanical shape. Background: premium advertising gradient, rich cool violet fading to luminous white, soft lavender glow, airy negative space, atmospheric depth no additional flowers, stems, or botanical elements. Soft diffused studio lighting, gentle highlight roll off, cool luminous highlights, natural diamond sparkle, realistic white gold reflections, real contact shadow, true macro depth of field, 100mm macro lens, real studio photography, not CGI, no text, no logo, no watermark. Negative prompt: background flowers, extra stems, ring inside bloom, ring on stem, deformed lily, warped petals, thick band, oversized prongs, halo, pav, side stones, floating ring, no contact shadow, blurry ring, CGI, 3D render, neon gradient, cheap background.