 Kauri gum is a fossilized resin detracted from kauri trees ( Agathis australis ) , which is made into crafts such as jewellery . Kauri forests once covered much of the North Island of New Zealand , before Māori and European settlers caused deforestation , causing several areas to revert to sand dunes , scrubs , and swamps . Even afterward , ancient kauri fields continued to provide a source for the gum and the remaining forests . 
