A company looking for lithium in hot springs in Cornwall has found the metal at "globally significant" levels.
Global demand for lithium, which is used in batteries for mobile phones and electric cars, is increasing.
Cornish Lithium has been sampling deep geothermal waters near Redruth and said initial tests indicated some of the world's highest grades of lithium.
Chief Executive Jeremy Wrathall said the results gave Cornwall "potential for a real new industry".
He said: "This is an exciting step towards the realisation of low-carbon lithium extraction from geothermal waters in Cornwall."
The company said samples taken from between 0.37 miles (600m) to 3.2 miles (5.2km) deep indicated the best overall chemical qualities for lithium encountered in published records for geothermal waters in the world.
Average lithium concentrations were found to be high at 220 mg/l with low concentrations of total dissolved solids - relative to other geothermal waters in the world - and "ultra low" concentrations of magnesium, a metal that makes processing more expensive.
Cornish Lithium and Geothermal Engineering Limited, the developer of the United Downs Geothermal Power Project, were recently awarded funding from the government to build a pilot lithium extraction plant.
The £4m project will trial direct lithium extraction, which removes dissolved lithium compounds from water without the need for the large evaporation ponds that are used in arid regions of South America.
Mr Wrathall said if the pilot was successful they were looking at three to five years before production could begin but "that coincides very neatly with when Britain really transfers to electric vehicles in a big way".
He said there was potential in Cornwall for combined geothermal and lithium extraction plants at other locations.
Two independent laboratories were asked to confirm the grades of lithium.
Rob Bowell, from SRK Consulting, which provides services to mining and exploration companies, said: "The lithium grades ... are globally significant."
Mr Bowell said it was "a fantastic opportunity for Cornwall to lead the charge on environmentally responsible extraction of this critical raw material".