One week. That is the deadline the mines and energy minister, Alexandre Silveira, set on Wednesday (16) for Brazil to see the first "concrete results" of its new critical minerals law, according to news site g1. In practice, the government has promised to unveil company investments in refining and processing inside the country, stages of the supply chain that are currently done mostly abroad and that hold the better qualified jobs.

The announcement came at the ceremony where President Luiz Inácio Lula da Silva signed the National Policy for Critical and Strategic Minerals into law. Congress had finished the text in early September: the Senate passed the bill on September 2 in a symbolic vote, with support from the opposition, according to state news agency Agência Brasil. The law authorizes a guarantee fund (collateral that helps companies borrow) with a federal contribution capped at 2 billion reais, plus a tax credit (a discount on taxes owed) of up to 5 billion reais, paid in yearly installments of 1 billion reais between 2030 and 2034.

To size the numbers: the annual cap on the tax break equals roughly 5 reais per Brazilian per year. The budget to map the country's geology, now 8 million reais at the National Mining Agency, will rise to 300 million reais next year, nearly a 38-fold increase, according to Silveira. That mapping shows where economically viable ore sits, information that is still missing for much of Brazilian territory.

Understand: what critical minerals are

Rare earths are a group of 17 chemical elements used in the permanent magnets of electric motors, smartphones and wind turbines. They are part of the broader group of critical minerals, which includes lithium, cobalt, nickel, graphite and copper, raw materials for batteries, solar panels and defense equipment. Despite the name, they are not exactly rare: they are spread across the world, but in low concentrations, which makes extraction expensive.

Brazil holds the world's second largest rare earths reserve, about 21 million tonnes, behind only China, according to the United States Geological Survey. The global race for the sector heated up last month, when the American company USA Rare Earth moved forward with a purchase of Serra Verde, the only rare earths miner operating in Brazil. At the signing ceremony, Lula said that "the wealth of Brazil has a single owner: the Brazilian people".

There is skepticism. The association of mining municipalities, AMIG Brasil, fears the investments will flow to other regions, leaving only the impacts of mining behind. Bruno Milanez, a professor at the Federal University of Juiz de Fora, told Agência Brasil that the incentives are insufficient to industrialize rare earths in the country.