St George Mining's Araxá rare earths and niobium project has put some serious numbers on the board in Brazil, with the company delivering a massive resource upgrade over the deposit that catapults into globally significant territory.

The company today unveiled a total JORC compliant resource of 111.2 million tonnes grading a notable 3.57 per cent total rare earth oxides, or “TREO”, and 0.57 per cent niobium pentoxide.

The result marks a 57 per cent increase on the previous total resource from March this year. However, the real kicker is the stunning 155 per cent increase in the higher-confidence measured and indicated, or “M&I”, categories, which now stand at a combined 75.2 million tonnes at 3.64 per cent TREO and 0.58 per cent niobium pentoxide.

The massive boost in M&I tonnes provides a rock-solid foundation for the company’s ongoing development studies. St George says its Araxá project now contains more M&I tonnes of the lucrative magnet rare earths neodymium and praseodymium, or “NdPr”, than the major global producers Lynas Rare Earths in Western Australia and MP Materials in California.

The total estimated mineral resource now contains an eye-watering 760,000 tonnes of combined neodymium and praseodymium oxides (NdPr) and 630,000 tonnes of niobium pentoxide, a milestone which St George says establishes its Araxá deposit as hosting the world's largest undeveloped measured niobium resource.

The upgrade is the culmination of the company's relentless drilling campaign over recent months that has consistently delivered spectacular intercepts from surface. Standout results include a massive 178.7m hit grading 4.34 per cent TREO and 0.75 per cent niobium pentoxide right from surface level.

And it seems the story is far from over. The deposit remains open in all directions, with resource definition drilling currently underway at the recent East Araxá discovery, just 1 kilometre from the main resource area. St George is already flagging a further mineral resource estimate update for the fourth quarter of this year.

The project’s mineralised geology is particularly favourable, with the deposit starting from surface and contained entirely within a weathered, free-digging profile that is amenable to simple open-pit mining with minimal need for blasting, crushing or grinding.

St George Mining executive chairman John Prineas said: “Today’s announcement of such a major upgrade to the size and quality of the resource at our 100%- owned Araxá Project further stamps the credentials of the project as the most significant undeveloped rare earths and niobium project worldwide. The Araxá MRE is the largest undeveloped niobium Measured Resource in the world."

Located in the Tier 1 mining jurisdiction of Minas Gerais, Brazil, the project boasts outstanding logistics. It sits just 6km from the city of Araxá and adjacent to existing major mining operations, including Brazilian miner CBMM’s world-leading niobium mine, providing access to established infrastructure, a skilled workforce and a supportive government.

St George has also been making serious headway on the metallurgical front. Test work earlier this year successfully produced separate high-grade concentrates, delivering a niobium concentrate grading 39.6 per cent niobium pentoxide at a solid 54.3 per cent flotation recovery. The process also yielded a rare earths concentrate in the tailings grading an impressive 15.7 per cent TREO, confirming the potential for a dual-processing operation. This builds on a historical pilot plant study from 2013 that produced rare earth oxalate at up to 99 per cent purity with 86 per cent recovery.

With a war chest of $98.2 million in pro-forma cash and the backing of Gina Rinehart’s Hancock Prospecting as its largest shareholder with a 10.3 per cent stake, St George is well-funded to push ahead.

The company has already locked in a suite of strategic downstream partnerships in the US, Europe and Brazil to support its development, including alliances with US magnet-maker REalloys and European engineering giant Tecnicas Reunidas.

With engineering heavyweight Worley appointed as its feasibility technical adviser and economic studies due to land before the end of the year, St George appears to have all its ducks in a row, which is possibly reflected by the company's 9 per cent share price rise to close at 8.9 cents on Tuesday with the company now boasting a market cap a little over $400M.

Having just delivered a resource of a scale that would make many a major miner green with envy, St George has firmly established Araxá as a project of global significance. As the drills continue spinning their rods and development studies progress, the Perth-based explorer looks to be rapidly rounding the corner with serious momentum towards becoming a developer.

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