MORE than 3,000 years ago axes made of glass were used to chop wood in Papua New Guinea.
Flaked tools made of the natural glass obsidian and found at ancient quarries in New Britain pose an intriguing problem because they are shaped like axes, but glass is generally considered too brittle a material for chopping. But is it?
To test if these obsidian axes were functional, we made replicas using the same kind of obsidian.
The flaked tools lashed onto handles like axes and adzes were found to be surprisingly effective at chopping soft wood.
Analysis using high powered microscopy then revealed the same wear patterns had formed on the cutting edge and handles of the experimental and archaeological tools. The obsidian artefacts were probably used as special purpose tools, perhaps to make items like masks or shields for ceremonies and rituals.