Now GNS Science researchers Simon Cox and Nick Mortimer have received a $927,000 Royal Society of New Zealand Marsden grant to find out why it is so strong, and use the research to help develop super-tough synthetic materials.
"Nephrite jade and pounamu are unusual rocks in that they have metal-like toughness — in other words they are very resistant to fracture," Dr Cox said.
"Why this should be is a scientific mystery. The mineralogical explanation of pounamu’s physical toughness remains elusive."
The minerals in pounamu were all "fairly soft", yet the rock was tough.
"This makes it excellent for carving, and for creating objects which keep a sharp edge.
"We think the longstanding explanation — of twisted mineral fibres — is wrong.
"So we will be testing other theories — including ultra-fine grain size and stored strain."
Dr Cox said he would be working with Ngai Tahu, pounamu artisans and colleagues from the University of Otago, using materials science and matauranga Maori to explain the special physical properties and uses of nephrite jade.
"With its cultural, geological, archaeological and materials science significance, this project could rewrite the jade textbooks of the world and lead to better management of this precious resource."
The research project is among more than $20 million worth of Marsden grants given to Otago-based researchers.
Twenty-four Otago academics also received 2022 Marsden grants, worth a total of $19.8 million.
In total, 113 new projects across New Zealand received Marsden grants worth more than $77.391 million, which will be invested over the next three years.
— All Otago project details: www.odt.co.nz
