This was perhaps one of the oldest mines on the island, as indicated by several historical documents and findings from ancient times, and it was certainly one of the most important, above all for the mining and processing methods used. Its industrial history too coincides with the great awakening on the island following the full union with the mainland states of the Savoy kingdom. When Monteponi opened under Galletti's management (1851), some prospecting also began in Monte Barlao which stood opposite, by both experts and amateur geologists. However, the first mining concession was only awarded in 1867 to the English Gonnesa Mining company Ltd, after clearing the ground of the original discoverers by charging a hefty entry tax.
The British engineers excelled in mining know-how, and at San Giovanni they immediately obtained excellent results, having planned mining operations in a rational and effective manner, and having adopted work organisation methods that were truly innovative for those times. According to a report dated 1872, the company's profits in sterling per employee were already in line with those obtained in the mines of Cornwall.
The mine's high yields and extensive deposits attracted the attention of Lord Thomas Brassey, who purchased it and, at the end of the 19th century merged operations with his Mineraria di Pertusola. This was the start of a period of great development, also due to discovery of an important seam of calamine, which was also rich in lead. At that time, the workforce reached one thousand, for the most part living in the small village of Bindua, at the foot of the mountain. The great modem ore processing plant known as ldina boosted the mine's profitability and improved the quality and quantity of production.
The owner's sudden death in 1919 did not affect the mine's performance, as the new French shareholders confirmed all his expansion projects. San Giovanni was among the mines which weathered better the crisis of the 1960s, despite the exit of the Rothschild multinational and the entry in 1969 of public capital with the Piombo Zincifera Sarda and subsequently in 1982, with Samin of the ENI group. But this was to be the beginning of the end, and final closure took place at the beginning of the 1990s.
