The new estimate stands at 1.37 million indicated tonnes and 723,000 inferred tonnes of lithium carbonate equivalent, or LCE, for a total of 2.09 million tonnes of LCE.
"We foresee continued consolidation within the lithium space and this updated report adds significant value to Spearmint," the company's president James Nelson said.
"The four holes drilled in 2022 allowed us to significantly expand the resource to the west and based on this report, further potential increases to this resource estimate are possible," he added.
He noted US President Joe Biden's March 31 enactment of the Defense Production Act to increase domestic production of strategic and critical materials, which includes lithium.
"This could provide a major catalyst and sector momentum for developing domestic sources of battery metals," he said.
The deposit is 55 km west of the town of Tonopah and is accessed off paved State Highway 265, which terminates at the Silver Peak mine, and then by country gravel roads, the company said.
It directly borders Pure Energy Minerals and Cypress Development Corp; the ‘Elon Lithium Brine Project' which has access to some of the deepest parts of the only lithium brine basin in production in North America, it said.
Spearmint also has the Goose Gold project and Perron-East gold project in the Abitibi greenstone belt of northwestern Quebec, Canada.
Spearmint's share price was up 6% day on day at C$0.085 (US$0.07) on June 19. The company has a market capitalization of C$21.67 million.