Territory Uranium and Arafura Resources are sitting on potentially big deposits of one of the most in-demand resources in the world - rare earths.

The minerals are used in a range of technology from iPhones and flat screen TVs to energy efficient lamps.

A kilo of rare earths can sell for up to $100,000.

It is so lucrative that when Arafura recently declared to the Australian Stock Exchange it had found signs of a significant resource at Nolan's Bore, 100km north of Alice Springs, its share value shot up 61 per cent.

Territory Uranium has also found rare earths near Pine Creek, 210km south of Darwin.

The Japanese, the world's second largest consumer of rare earths, have shown keen interest in the finds.

At a recent Mineral Investment Seminar held in Sydney, 75 Japanese investors came to hear NT Minister for Resources Kon Vatskalis spruik the Territory's rare earths.

"We promote that one now aggressively in Japan," Mr Vatskalis said.

Securing a reliable source of rare earths has become a top priority for Japan since their main supplier China cut all exports to the country a month ago after Japan arrested a Chinese fishing boat captain.

China supplies 95 per cent of world demand for rare earths, which is 110,000 tonnes a year.

But in the second half of this year China cut its export quota by 70 per cent, wanting to keep rare earths for its domestic market.

With China hoarding their rare earths, Arafura expects to become an essential part of the supply matrix over the next decade.

The company aims to produce 20,000 tonnes of rare earths a year, planning to begin production in 2013.

Arafura is expected to produce 20,000 tonnes of rare earth oxides a year from its Nolans Project, with initial production scheduled for 2013.