Colorful Glass Beads from the Kanduli Shoal Shipwreck [Archaeological Studies]

Beads are said to be one of the oldest forms of human expression. They were used as decorations, burial offerings, and other functions relating to the economic, social, and artistic expression of culture. Among other materials, glass had been most extensively used in manufacturing beads due to its low cost, strength, and easy manipulation. Their portability and durability made them excellent trade and exchange materials as evidenced by the number of glass beads found in terrestrial and underwater archaeological sites.

Over 200 glass beads were recovered from the 16th century CE shipwreck that sunk in Kanduli Shoal (also known as Royal Captain) near Palawan Island. The vessel may have plied the Southeast Asian intra-regional trade and was on its way to Borneo from China when it struck the then uncharted reef that led to its demise.

 

In 1985, World Wide First (WWF) led by French underwater archaeologist Franck Goddio collaborated with the National Museum of the Philippines (NMP) surveyed and consequently excavated the shipwreck.

 

Bead Identification Process Flowchart developed by Archaeology Division Senior Museum Researcher Rey Santiago

The beads recovered were monochrome in colors red, blue, white, and yellow. The glass bead assemblage of Kanduli Shoal wreck was reportedly similar to the beads found in Bolinao, Pangasinan (14th – 15th century CE); Calatagan, Batangas (14th – 16th century CE); Santa Ana, Manila (12th – 16th century CE); and Porac, Pampanga. All beads found in the wreck have a circular conical hole suggesting its use as necklace or bracelet.

 

The analysis of the glass beads showed a wound manufacturing technique and high levels of lead (Pb) in their chemical composition. These characteristics indicate a Chinese bead type. However, the lack of archaeologically excavated primary glass production sites makes it difficult to confirm the exact bead manufacturing sites as there are only few evidences of glass working in China.

Drip-winding technique (Francis, 2002)

 

How are wound-type glass beads made? A hot and molten rod of molten glass is winded around a metal wire called mandrel. The bead maker heats and winds the glass in front of a flame or any heat source. The resulting beads are sometimes decorated with any inlays while still soft. After cooling, these are then stripped from the mandrel. Swirl marks or striations encircling the surface of the bead’s hole make their source identifiable.

Bead Classification (Beck, 1928)

A marker for identifying Chinese beads are the high level of lead content. Lead and barium (Ba) helps in lowering the melting point of glass making it easier to work with. They also give the glass additional brilliance.

 

The colorants are also important in identifying bead technology. For instance, the addition of copper (Cu) to the melting paste provides a green or red hue depending on manner in which it is added while the addition of cobalt (Co) produces blue color. It was also said that the Chinese produced beads to imitate jade and other semiprecious stones.

Archaeological study is very important in supporting accurate interpretation of past events, which helps in reconstructing our history. When a site is disturbed or pilfered, we lose information forever without the significant context to assist us in piecing together our story. This is much more valuable than the selfish individual’s monetary gain or enriching their personal collections. Our heritage and recounting its narrative through material culture benefits future generations and our aspirations as a nation. If you see or have knowledge of sites being looted, report to your local government authorities immediately or contact the closest NMP office near you.

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Text and photos by NMP Maritime and Underwater Cultural Heritage Division

©National Museum of the Philippines (2021)