Create a contemporary fine-art image of translucent porcelain shells arranged as a tidal spiral on a deep indigo surface. Edge each shell with delicate cobalt glaze cracks. Use a soft museum spotlight to cast long overlapping shadows, emphasize tactile ceramic detail and photograph the installation from a high oblique angle. Keep the mood serene, minimal and slightly surreal in a square composition. No text, no logo, no watermark, no clutter and no plastic-looking material.