I grew up in NZ and have a pounamu/greenstone toki I inherited from my parents.
I miss New Zealand dearly and want to wear it, but I feel that as a white person whose great grandparents came to new Zealand from Ireland, it would be cultural appropriation?
I'm unsure and haven't lived in New Zealand for over a decade, so I don't know the stance on crackers wearing Maori symbols.
Speaking with a Maori friend on this, and as someone of pakeha descent myself, Its generally ok for Pakeha to wear generalised NZ symbols as long as they aren't those of a particular nation (Iwi) and you're actually wearing them honorably as they should be worn.
Just be aware, you're representing both Pakeha and Maori and should show due deference and respect to the traditions you've adopted. Some Maori might still disagree but you're just gonna have to wear it.
A greenstone should only be worn as a deeply special gift, and I think this counts.