Archaeologists have discovered two forms of jade that can be found across Taiwan through the Philippines, East Malaysia, central and southern Vietnam, and even extend to eastern Cambodia and peninsular Thailand. These two forms are called linling-o penannular earring with three pointed circumferential projections and the double animal-headed ear pendant. The forms are very similar in size and range from about 30-35mm in diameter. Furthermore, radiocarbon dates have dated these forms in Southeast Asia from around 500 BC to 500 AD.[12] The electron probe microanalysis shows that the raw material of these two types of artifacts was nephrite jade from Taiwan called Fengtian nephrite. Evidence recovered from multiple sites from Taiwan, the Philippines, and the mainland southeast Asia suggests that Taiwan was the main source of the exchange of this kind jade. During the Iron Age of Southeast Asia, there may have been skilled craftsmen traveling from Taiwan to southeast Asia along the coastline of the South China Sea, making jade ornaments for local inhabitants