Chatham Rock's chief executive Chris Castle last week announced a 100% owned subsidiary, Pacific Rare Earths Ltd, had been formed.
"This company has been formed to project-manage a work programme aimed at quantifying the extent, value and recoverability of rare earth elements and other potentially strategic or valuable minerals contained in the rock phosphate nodules on the Chatham Rise," Mr Castle said.
After exploring for phosphate nodules from the Chatham Rise, Chatham Phosphate had announced last year it also found rare earths and other valuable minerals within its permit area. The finds included cerium, lanthanum, neodymium, praseodymium, yttrium, cobalt, rubidium, cesium, germanium, gallium, strontium, thallium and tungsten.
Many of the rare minerals are being touted for use in "green energy" solutions, including new generation batteries, solar panels and electric vehicles.
However, seabed mining will not be occurring in New Zealand soon.
While Chatham already has a mining licence for the Chatham Rise, its first marine consent application to the Environmental Protection Authority was rejected in 2015, and it is in the process of reapplying by the end of this year.
A would-be Taranaki ironsands miner, Trans-Tasman Resources, had its second marine consent overturned last month in the High Court, after a spirited challenge from environmentalists, iwi, communities and fishing companies.
Combined, Chatham Rock and Trans-Tasman have spent well over $100million to date on research and development and numerous legal challenges.
Chatham Rock wants to suction up 1.5million tonnes of phosphate nodules from the Chatham Rise seafloor, about 250km west of the Chatham Islands, in depths of up to 450m.
Mr Castle said of the 17 recognised rare earths, 15 were found to be present in Chatham Rise rock phosphate nodules, as well as other valuable minerals.
Those included nickel, cobalt, chromium, vanadium, zirconium, fluorine and strontium, he said.
"Collectively these minerals, if they can be efficiently extracted as by-products, represent not only an immensely strategic asset for New Zealand, but could significantly improve the already attractive forecast project economics," Mr Castle said in a release to the Toronto and NZX stock exchanges.
Mr Castle said the recovery of rare earths from seafloor muds would involve development of a new marine mining system, and so would be considered separately from Chatham Rock's phosphate nodule project.
He said the main challenge with the production of rare earths from the muds was extraction.
Given the "extremely favourable preliminary research", Mr Castle said Chatham Rock had started talks with skilled and funded external parties, both in New Zealand and overseas, to further develop a better understanding of the extraction and recovery potential of the rare minerals.