Shining like gold and soft like silk. The case of byssus samples coming from the Commodity Science Museum of the University of Bari

The word byssus is the zoological term used to call the fine but strong filaments of fibre beard produced by the mollusc Pinna nobilis. Byssus was the basic raw material used to make sea-silk, but, given that this species, endemic in the Mediterranean, is protected since 1992 [1], a renewed production of the beautiful iridescent amber-golden textile is essentially impossible. It is proved that the use of sea-silk dates back at least to the Roman age. In the modern times, up to the middle 20th century, Sardinia and Apulia (especially Taranto), were production centers of sea-silk and keep their importance still nowadays in the transmission of the knowledge of the ancient expertise, concerning the procedures of cutting, washing, drying, combing, spinning and -much rarely- waving of the fibre. The oral handing down of the know-how must be protected as part of our immaterial demoethno-anthropological heritage, because it is unfortunately gradually disappearing, like the concept of cultural heritage linked to the precious and rare textile that it produced. Only recently some effort has been made to draw attention on this subject with projects and exhibitions [2]. We studied samples of sea-silk stored at Commodity Science Museum of University of Bari “Aldo Moro” (Fig.1), where one valve, some pearls and all the different phases of crafting of this textile are represented, starting from the raw byssal threads up to the woven textile. The aim is to characterize morphologically and chemically the threads, especially the evolution and changing throughout the different working phases. In this way, there will be a scientific trace of what started as an oral tradition and is not yet nowadays widespread and well-known. We used different techniques like optical microscopy (OM), Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM-EDS) and Inductively Coupled-Mass Spectrometry (ICP-MS). The results obtained show how the fiber of the Sea-silk changes until the achievement of the golden “soul of the sea” [3].