West New Britain occupies the western half of New Britain Island. It is populated by people from all over Papua New Guinea, many of whom come to work in the plantations and mills. One fourth of the population was born off the island, however, the highest rate for any province. The town of Talasea is a centre for the manufacture of shell money: obsidian, or volcanic glass, that is used in the manufacture of knives, spears and arrows. Shell money was used for trade from about 3000 BC until recent times.