Pounamu is the Māori name for the green to greenish-white hardstone of the South Island of New Zealand, encompassing nephrite jade and the serpentine variety known as tangiwai or bowenite. The term is the proper designation in New Zealand legal and cultural contexts and has been adopted by GIA and other international gemmological bodies as the regionally appropriate name for this material. Pounamu has been worked by Māori for at least 700 years for tools, weapons, and the personal ornaments — hei-tiki, hei-matau, pekapeka, kuru — that remain among the most recognisable forms in Pacific material culture.

Mineralogy

Most pounamu is nephrite, a calcium-magnesium-iron amphibole of the tremolite-actinolite series with the formula Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂. Its toughness — the highest of any natural material on the practical-strength scale used by carvers and engineers — derives from a felted microstructure of interlocking acicular amphibole crystals, which resist fracture even when individual crystallites are deformed. Nephrite is hardness 6 to 6.5 on the Mohs scale, specific gravity 2.90 to 3.10, and refractive index near 1.61. Tangiwai, the serpentine variety, is softer (about 5 to 6) and translucent, with a glassy lustre that distinguishes it from amphibole pounamu.

Pounamu colour ranges from near-white through pale grey-green and apple-green to deep saturated green and almost black. Traditional Māori classification recognises a series of named varieties — kawakawa, kahurangi, inanga, totoweka, and others — each defined by colour, translucency, and inclusion pattern. These names remain in current trade use among Māori carvers and South Island dealers and predate any Western gemmological classification by centuries.

Sources and statute

Pounamu is found in situ in the schist belt of the Southern Alps and as boulders and pebbles in the rivers and beaches of the West Coast and Otago, with the Arahura, Taramakau, Hokitika, and Cascade rivers being the historically most productive sources. Tangiwai (bowenite) comes from the Anita Bay area of Milford Sound in Fiordland.

Under the Ngāi Tahu (Pounamu Vesting) Act 1997 — passed as part of the wider Ngāi Tahu Claims Settlement Act 1998 — naturally occurring pounamu in the South Island is vested in the iwi (tribe) Ngāi Tahu. Mining, collecting, and trade in pounamu of South Island origin are therefore subject to Ngāi Tahu authorisation; certified pounamu carries provenance documentation, and the iwi operates an authentication scheme that matters both for legal compliance and for buyers seeking ethically sourced material. Pounamu collected before the vesting and pounamu sourced outside South Island Crown land are not covered by the Act, but the cultural protocols around respectful use apply across the trade.

Working and identification

Traditional Māori working of pounamu used sandstone abrasives, water, and shaped wooden or bone tools — a slow, reductive process that produced the distinctive carved forms of the pre-contact period. Contemporary carvers use diamond saws, lapidary wheels, and rotary tools but retain the design vocabulary of the historical taonga (treasures). The toughness that made nephrite ideal for adze blades makes it equally suited to fine carved pendants that survive generations of wear.

Identification distinguishes pounamu from serpentine simulants (lower hardness, lower SG), from chrysoprase and green agate (higher RI for chalcedony, distinct microstructure), and from jadeite (different RI, different absorption spectrum, different inclusion suite). Reputable laboratory testing is the standard for high-value pieces, particularly those traded as antique taonga.

In the trade

The pounamu market is bifurcated. Authorised carved pieces from Ngāi Tahu certified sources, with provenance documentation, command significant premiums and trade primarily through galleries, the iwi's own retail channels, and specialist dealers. Generic green nephrite labelled as pounamu without certification is common in tourist channels and online marketplaces; some of this material is genuine pre-Act stock, some is non-South Island nephrite (from British Columbia, Siberia, or Xinjiang) sold under the local name. Buyers seeking authentic pounamu should ask for the Ngāi Tahu authentication mark and the carver's name and lineage.

Care

Pounamu is exceptionally durable. Mild soap and warm water are sufficient for cleaning; ultrasonic cleaning is generally safe for solid carved pieces but should be avoided for older taonga and for pieces with cracks or fillings. Pounamu darkens with skin oils over years of wear, a patina that Māori tradition values rather than restores.

Further reading

• GIA — Jade reference
• GIA Gems & Gemology — nephrite articles
• International Gem Society — jade reference
• ICA — Jade