What natural material, a type of nephrite jade found in South Island rivers, was highly prized by Māori for making tools, weapons, and heirloom ornaments?

• A Obsidian
• B Basalt
• C Pounamu (greenstone) ✓
• D Flint

Pounamu was so valued that it was traded across the country, and the Ngāi Tahu iwi are its legal guardians under the Ngāi Tahu Claims Settlement Act 1998.