RIO DE JANEIRO, March 2 (Reuters) - Australia's St George Mining SGQ.AX said on Monday that the estimated amount of mineral resources at its Araxa rare earths niobium project in Brazil has been upgraded by 75%.

• The estimate is a result of studies that the mining firm started in July, 2025, said St George, which fully owns the project, in a statement.

• The mineral resource estimate (MRE) of the project was seen at 70.91 million metric tons from previous about 40 million tons, the firm said.

• Rare earths content as measured by total rare earth oxide (TREO) was at 4.06%, while niobium content (Nb₂O₅) was at 0.62%, it said.

• The MRE "includes niobium that occurs in the same cells as that TREO", it said, noting a separate modelling indicated further 24.56 million tons of niobium could be included.

• The estimates were made following the international JORC 2012 standard, and modeled by SRK Consulting, according to the statement.

• The estimates could further increase since they do not include 41 drill holes concluded, 50 planned and the East Araxa discovery, the firm said.

(Reporting by Marta Nogueira in Rio de Janeiro; Writing by Andre Romani; Editing by Sarah Morland)

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