What are the tikanga for buying, wearing and caring for pounamu?

Pounamu is a prized taonga for both Maori and non-Maori alike and increasingly its gifted for significant life events and celebrations. But as interest around pounamu grows, what are the tikanga surrounding the buying, wearing and caring for it? In-Depth Maori journalist Ella Stewart spoke to the experts about the dos and don't around pounamu.