Each spring, under the cover of darkness and guarded by members of the Italian Coast Guard, 62-year-old Chiara Vigo slips on a white tunic, recites a prayer and plunges headfirst into the crystalline sea off the tiny Sardinian island of Sant’Antioco.
Using the moonlight to guide her, Vigo descends up to 15m below the surface to reach a series of secluded underwater coves and grassy lagoons that the women in her family have kept secret for the past 24 generations. She then uses a tiny scalpel to carefully trim the razor-thin fibres growing from the tips of a highly endangered Mediterranean clam known as the noble pen shell, or pinna nobbilis.
It takes about 100 dives to harvest 30g of usable strands, which form when the mollusc’s secreted saliva comes in contact with salt water and solidifies into keratin. Only then is Vigo ready to begin cleaning, spinning and weaving the delicate threads. Known as byssus, or sea silk, it’s one of the rarest and most coveted materials in the world.