
The Star of the South, also known as Estrela do Sul, is a diamond found in Brazil in 1853. The diamond is cut into a cushion shape and weighs 128.48 carats (25.70 g). The Star of the South is graded as a type IIa diamond, with a colour grading of light pinkish-brown and a clarity of VS2. At the time of discovery, the diamond weighed 254.5 carats (50.9 g). It has passed through the hands of many owners, and its last known purchase was by Cartier store, when it was sold by Rustomjee Jamsetjee of Mumbai. The light reflected by the diamond is white, and the refracted light is of a rose tint. This gives the diamond its light pinkish-brown hue.
The diamond was found by a slave girl in 1853, at the Bagagem Diamond Mines in Brazil. It was handed over to her master, Casimiro de Tal, who rewarded her for finding the diamond by granting her freedom and a pension for life. Casimiro de Tal later sold it for £3,000, a price far lower than its actual value. The buyer deposited the diamond at the Bank of Rio de Janeiro for £30,000.
The uncut diamond was passed through the hands of several buyers, until it was bought by Coster’s Establishment of Amsterdam for £35,000. It was then cut into an oval cushion shape by a cutter called Voorsanger of Coster’s Establishment, at a cost of £500.
It was purchased by Halphen and Associates of Paris, a syndicate of diamond merchants led by Messrs. Halphen, who named it Estrela do Sul, or Star of the South. The syndicate exhibited the diamond 1862 at the London Exhibition, and again 1867 at the Paris Exhibition. On both occasions, the Star of the South received considerable attention. The diamond was later sent to a diamond dealing house in India, where negotiations were carried out to sell it to a Maharajah for a price of £110,000. However, this deal was not successful and the diamond was returned to Halphen and Associates.
During the diamond’s stay in India, Prince Mulhar Rao of the royal family of Gaekwad got to know about the stone. He instructed E. H. Dresden of London to purchase the diamond, who purchased it from Halphen and Associates for £80,000 on behalf of the prince. The Star of the South was in the possession of the Gaekwad family for several years. It was later mounted on a necklace along with the 78.5 carats (15.7 g) English Dresden diamond. In 1934, Prince Mulhar Rao’s son had told Robert M. Shipley, an American gemologist about this. In 1948, the Maharani Sita Devi of Baroda, was photographed wearing the necklace at her husband Maharajah Pratapsinh's birthday party.
The Star of the South was later purchased by Rustomjee Jamsetjee of Mumbai, who sold it to Cartier in 2002.