Wellington, July 25 NZPA - One of New Zealand's least publicised non-metallic minerals, halloysite, is highly sought-after and exported to 23 countries to make quality porcelains.

The high quality china clay is mined in Northland, and only two of the four deposits at Matauri Bay and Mahmahi have so far been worked. The two active quarries and buffer areas cover 178ha, giving an annual gross revenue of about $73,000/ha.

Halloysite is the only industrial mineral entirely exported.

Potential mineral and energy resources include:

* Non-metallic minerals, in addition to halloysite: New Zealand is producing about $40 million a year worth of industrial minerals such as amorphous silica, bentonite, diatomite, dolomite, perlite, pumice, serpentine, silica sand and zeolite.

* Oil and gas: gas accounts for more than 20 percent of the country's primary energy supply; further exploration stands to increase this.

* Coal: New Zealand's largest energy resource. Feasibility studies are under way into $100 billion lignite deposits in Otago and Southland, with the energy content estimated at 20 times that of the Maui gas field before it was developed, and 35 times the country's current natural gas reserves

* Metals: Gold resource potential estimated at $45 billion, other metallic deposits worth about $100 billion. Gold produced in the past 20 years is worth about $6 billion at current prices. Ironsand is also being worked. Most potential resources are located on crown land, and an estimated 70 percent of hard rock mineral potential is on conservation land. Mining lobbyists blame an "unsupportive policy environment" for a fall in the rate of spending on metals exploration in 2007.

Source: Minerals Industry Association

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