Purpose -The purpose of this paper is to examine how, why and to what effect pounamu (New Zealand greenstone) came to be owned and managed by Ngai Tahu as part of a Treaty of Waitangi settlement. Design/methodology/approach -The value of pounamu to the Maori iwi Ngai Tahu, and the strategic importance and legislative mechanism of its vesting in Ngai Tahu are described. The current legal arrangements for pounamu are compared with those for other minerals and natural resources affected by Treaty of Waitangi settlements. The legally controversial issues of mandate, entitlement and enforcement that have arisen since the vesting are traversed. Findings -The return of pounamu was critical in settling Ngai Tahu's Treaty claims. Other natural resources have also been subject to Treaty claims, and some have been restored in whole or in part to Maori control. Pounamu is now owned and controlled by Ngai Tahu. Customary uses of pounamu are allowed, as potentially is mining that is supported by research. Current research aims to determine extraction rates for sustainable use, based on a definition of the resource as pounamu that is available for surface discovery and collection. The process of vesting pounamu in the legal entity established to represent Ngai Tahu was controversial, and complex disputes about customary rights and pounamu source(s) have dominated criminal proceedings undertaken to protect Ngai Tahu interests in pounamu. Originality/value -The story of pounamu provides an interesting example of a developing feature of resource management law and practice in New Zealand: resources that are owned and/or managed under a set of legal arrangements designed within the terms of settlement for a claim under the Treaty of Waitangi.