Ancient jades map 3,000 years of prehistoric exchange in Southeast Asia

Abstract

We have used electron probe microanalysis to examine Southeast Asian nephrite (jade) artifacts, many archeologically excavated, dating from 3000 B.C. through the first millennium A.D. The research has revealed the existence of one of the most extensive sea-based trade networks of a single geological material in the prehistoric world. Green nephrite from a source in eastern Taiwan was used to make two very specific forms of ear pendant that were distributed, between 500 B.C. and 500 A.D., through the Philippines, East Malaysia, southern Vietnam, and peninsular Thailand, forming a 3,000-km-diameter halo around the southern and eastern coastlines of the South China Sea. Other Taiwan nephrite artifacts, especially beads and bracelets, were distributed earlier during Neolithic times throughout Taiwan and from Taiwan into the Philippines.

Fig. 1.

Green nephrite jade ornaments and manufacturing debitage. (A–C) Nephrite lingling-o penannular earrings with three pointed circumferential projections. (A) Go Ma Voi, Vietnam (Institute of Archaeology, Hanoi). (B) Uyaw Cave, the Tabon Complex, Palawan, Philippines (National Museum of the Philippines, Manila). (C) Duyong Cave, the Tabon Complex, Palawan, Philippines (National Museum of the Philippines, Manila). (D) Double-headed animal nephrite ear pendant from the Philippines (collection of Ramon Villegas, Manila). (E–O) A suggested manufacturing sequence for lingling-o ear pendants, as reconstructed from discarded raw material recovered at Pinglin, eastern Taiwan, and Anaro, Itbayat Island, northern Philippines (these pieces do not come from a single manufacturing event). Stage 1: E is a triangular discard from a cut square preform ≈1 cm thick (F), the intention being to shape an octagonal blank (see I); from Pinglin, eastern Taiwan. Stage 2: G and I represent the first bracelet to be drilled from an octagonal blank, in this case, ≈2 cm thick, leaving a round core (H). Presumably, the original bracelet outer diameter exceeded the diameter of available bamboo drills, hence this method of manufacture, allowing the projecting corners to be ground off to give the bracelet a round exterior; from Pinglin. Stage 3: J represents a second (or perhaps third) bracelet drilled from a large core; from Pinglin. Successive bracelet and flat ear ring removals could have continued from this point, until the remaining core became too small to use. Stage 4: Items K–O all come from Anaro, Itbayat, northern Philippines. We infer that some large discs produced by large bracelet manufacture were brought to Anaro from Taiwan, each to become the blank for four lingling-os, drilled in quadripartite fashion (P). O is a drilled core from the center of a lingling-o; K–M are discards from around and between the smaller drilled circles. N is part of a much thinner ring drilled out to help delineate the projections, which were probably drilled finally at 90° to the axis of the core and finished by manual shaping (see A–C).

Fig. 2.

Sites with nephrite artifacts in Southeast Asia.

Fig. 3.

The distribution of Taiwan nephrite artifacts in Southeast Asia. The green zone represents the currently known distribution of Taiwan nephrite artifacts. The green triangle locates the Fengtian nephrite deposit. Yellow stars represent sites outside Taiwan with positively identified Fengtian nephrite artifacts (Taiwan itself has >108 jade-bearing sites, and these cannot be shown individually). Blue stars represent sites with jade artifacts of possible Fengtian origin, based on visual examination but not yet demonstrated in terms of mineral chemistry. Black circles represent sites that have identified nephrite of non-Fengtian origin. Identified Fengtian and possibly Fengtian nephrites: WG. Liyushan, Wangan Islands; QM, Nangang, Qimei Islands, Penghu Archipelago; JXL, Jialulan, eastern Taiwan; LD, Yugang and Guanyindong, Ludao Islands; LY, Lanyu High School Site, Lanyu Islands; AN, Anaro, Itbayat Islands; SG, Sunget, Batan Islands; SD, Savidug, Sabtang Islands; NGS, Nagsabaran, Cagayan Valley; KD, Kay Daing, Batangas; EN, Leta-Leta and Ille Caves, El Nido, Palawan; TC, Tabon Caves, Palawan; NC, Niah Cave West Mouth, Sarawak; AB, An Bang; GM, Go Mun; DL, Dai Lanh; GMV, Go Ma Voi; BY, Binh Yen (these five sites in Quang Nam Province, central Vietnam); GCV, Giong Ca Vo, Ho Chi Minh City; SS, Samrong Sen, Cambodia; UT, U-Thong, Suphanburi; BTDP, Ban Don Ta Phet, Kanchanaburi; KSK, Khao Sam Kaeo, Chumphon. Identified non-Fengtian nephrites: BTG, Uilang Bundok and Pila, Batangas; TK, Trang Kenh; YB, Yen Bac; MB, Man Bac; QC, Quy Chu; GB, Go Bong; XR, Xom Ren; GD, Go Dua; GL, Giong Lon. The red dashed lines enclose the major Austronesian language subgroups according to Blust (17) (SH/WNG, South Halmahera/West New Guinea).

Fig. 4.

Chemical compositions of nephrite jade artifacts. (A–E) Chemical compositions of the nephrite jade matrices of studied artifacts from Taiwan (A and B), the Philippines (C and D), and Borneo, Vietnam, and Thailand (E). The x and y axes represent, respectively, Si (atoms per formula unit on the basis of 23 oxygen) and Mg/[Mg+Fe²⁺] ratios, with the ideal chemical formula of calcium amphibole (Ca₂[Mg,Fe]₅[Si,Al]₈O₂₂[OH]₂). Relative standard deviations (1σ) of measurements are shown as error bars. (A) Symbols represent the WDS-EPMA results for 42 artifacts from 17 Taiwan sites. The upper shaded area encloses the chemical compositions of white-colored nephrite jade deposits from China (Liaoning, Xinjiang, Gansu, and Jiangsu Provinces) and Korea (Chuncheon) (–13). The lower shaded area represents the chemical compositions of green nephrite jade raw materials from the Fengtian deposit (eight hand specimens) and a nearby riverbed (nine hand specimens) in eastern Taiwan (11). The chemical boundary between tremolite and actinolite is marked by the Mg/(Mg+Fe) ratio of 0.90 (SI Table 3). (B–E) Analytical results obtained by the noninvasive LVSEM-EDS technique. The enclosed areas delimit the range of chemical compositions for Fengtian green nephrite jades. (B) Yugang and Guanyindong on Ludao Island, Lanyu High School on Lanyu Island, and Liyushan (Wangan Island) and Nangang (Qimei Island), Penghu Archipelago (12 artifacts from five sites, SI Table 4). (C) Anaro on Itbayat Island, Sunget on Batan Island, Savidug on Sabtang Island, Nagsabaran in the Cagayan Valley, and Kay Daing in Batangas, northern Philippines (30 artifacts from five sites) (SI Tables 4 and 5). The white nephrite (tremolite) artifacts from Uilang Bundok (UB: 1 adze) and Pila (PB: 3 adzes) in Batangas, and 12 adzes and two preforms from H. Otley Beyer's 1940s Batangas collection in the National Museum of the Philippines, are shown as gray symbols. In terms of their mineral chemistry and archaeological contexts, the white nephrites in the Philippines are probably of local origin (14) (SI Table 7). (D) Tabon Caves, Palawan (22 ornaments from nine sites: see SI Table 6). Seven lingling-o penannular earrings with three pointed circumferential projections and a single bicephalous (double-headed) animal ear pendant are plotted. (E) Artifacts from Niah Cave (Sarawak), Go Ma Voi (GMV) (central Vietnam), and Khao Sam Kaeo (KSK) in peninsular Thailand are represented here, including the lingling-o penannular earrings with three pointed circumferential projections from Niah and GMV (10 ornaments and worked pieces from three sites: see SI Table 4). White to green nephrite artifacts from northern Vietnam (MB, Man Bac; TK, Trang Kenh; XR, Xom Ren; GB, Go Bong; QC, Quy Chu; YB, Yen Bac), from central Vietnam (GMV; GD, Go Dua), and from southern Vietnam (GL, Giong Lon), shown by gray and black symbols, are not of Fengtian nephrite in terms of their mineral chemistry (see SI Table 7). (F) Chemical compositions of zinc-bearing chromite ([Mg,Fe,Zn][Al,Cr]₂O₄) inclusions in the surfaces of nephrite artifacts, analyzed by the noninvasive LVSEM-EDS technique. Symbols represent the value for zinc oxide (ZnO in wt %) and the Cr/(Cr+Al) ratio for each artifact. Because the chromite in Fengtian nephrite jade bears significant amounts of zinc (2 to 11 wt % in ZnO) (11) in comparison with the other possible nephrite (actinolite/tremolite) jade sources tested (Chara Jelgra, Siberia and Nanshan, Gansu), the Zn content provides a good clue for the identification of Fengtian nephrite.