Nephrite and Mica industries: a link towards the Austronesian world

Regarding the jade and jade-like artefacts unearthed om Khao Sam Kaeo, new research has explored the use of different raw materials and relations with inter-regional trade networks. Geochemical analysis offers a way to identify the geological sources of the stone materials, poten- tially involving long-distance movements. In conjunction with those findings, studies of workshop debris provide information about how the artefacts were produced and how the evident cra􀀀ing styles may have been linked across the regions of Mainland and Island Southeast Asia. Local cra􀀀 production is evident in workshop debris at the site. 󰀀e unearthed artefacts include complete objects and related worked agments such as drilled-out cores, cut square blanks, and small cut agments. Most of these materials were used for manufacturing ornaments such as the lingling-o penannular earrings, the double animal-headed ear pendants, bracelets, and pendants. In order to learn the geological sources of the green stones used to make these ornaments at Khao Sam Kaeo, 28 artefacts were examined through a series of non-invasive analyses by a low-vacuum scanning electron microscope ( LVSEM ) equipped with an energy dispersive X-ray ( EDS ) spectrometer. 󰀀e results show those objects and worked agments can be grouped into three major categories of nephrite jade (17 samples), green mica (8 samples), and quartzite (2 samples). 󰀀e geological sources included nephrite om Taiwan, mica om the Philippines, and quartzite om an unknown source. Among 17 specimens of nephrite, 12 of them are comparable to the Fengtian nephrite source in Eastern Taiwan. However, another 5 nephrite specimens were too weathered to analyze for making a final conclusion of their geological source. In addition to the nephrite om Taiwan, some of the artefacts were made of mica similar in chemistry to that om Mindoro Island in the Philippines. Khao Sam Keo became the first prehistoric jewellery workshop in Southeast Asia with a significant amount of mica-ornament production. Moreover, quartzite was used to produce a bracelet here.󰀀is study indicates that the stone jewellery production at Khao Sam Kaeo can be situated in a larger regional network or perhaps a number of such networks. Multiple overseas sources are evident in the raw materials. Additionally, the similar production method and ornament style of jade and mica link these findings to the contemporaneous traditions as documented at production sites distributed all around the South China Sea, such as in Southern Taiwan, the Philippines, and Southern Vietnam. Based on the new findings, two hypotheses are developed about the origins of the responsible cra􀀀smen and production techniques. 󰀀e first hypothesis proposes different backgrounds in ori- gin or training for the cra􀀀smen of jade versus the cra􀀀smen of mica objects. Each group owned the raw materials or could access the raw material. For nephrite, perhaps a group of specialised cra􀀀smen om Eastern Taiwan, Southern Vietnam, or the Philippines migrated into Khao Sam Kaeo. 󰀀e second hypothesis proposes that local cra􀀀smen at Khao Sam Kaeo knew the necessary skills for nephrite and mica production om other regions, but several points remain uncertain, such as how the skills were learned and how people obtained the raw materials om overseas. According to the archaeological findings at Khao Sam Kaeo, the site was strongly connected in extensive maritime trade networks, linking with Taiwan, the Philippines, Borneo, coastal Southern Vietnam, Cambodia, and beyond at approximately 400 through 100 BC. Future studies will be needed to understand how those overseas raw materials, techniques, and perhaps cra􀀀smen reached to Khao Sam Kaeo.