Microscopic Cross-Sectional Comparison of Fine-Paste Earthenware from a Production Center and a Consumption Site in Maritime Southeast Asia

Fine-paste earthenware held symbolic significance in Hindu and Buddhist rituals and domestic use in Southeast Asia. Despite the influx of Chinese glazed ceramics from the ninth century onward, these locally produced vessels continued to circulate widely until the fourteenth century along maritime trade routes extending from northern Sumatra and Java to the southern Philippines and the Thai–Malay Peninsula. Integrated petrographic, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Spectroscopy (EDS) analyses were employed to compare fine-paste earthenware from the Kok Moh production center in Songkhla Province, Thailand, and the Kota Cina consumption site in northern Sumatra, Indonesia. Petrographic observations indicate broadly similar mineralogical compositions in samples from both sites, consistent with the use of kaolin-rich clay materials. FESEM reveals that Kok Moh samples exhibit relatively dense and homogeneous microstructures with more continuous matrices, whereas Kota Cina specimens display coarser textures, more distinct mineral inclusions, and less consolidated matrices. EDS elemental mapping further demonstrates a more uniform distribution of major elements in the Kok Moh samples. Although both groups share broadly similar silica–alumina compositions, the observed microstructural differences suggest variations in clay preparation and firing practices rather than major differences in raw material selection. Comparison with published data from Nakhon Si Thammarat supports an association with kaolin-rich clay resources in southern Thailand. In contrast, the examined ceramics differ from fine-paste wares reported from northeastern Thailand, Myanmar, and India. These findings suggest that maritime Southeast Asian fine-paste ware developed as a localized technological tradition shaped by regional resources, production practices, and maritime exchange networks.