Boulle worked for the De BeersDiamond Trading Company for ten years, in Zaire, Sierra Leone and Antwerp, Belgium, and then established Boulle Inc. in Dallas, Texas. In 1984 he began exploring for diamonds, first in Minnesota, then in Arkansas. In 1987 he formed Arkansas Diamond Development Co., to carry out exploration work on the Crater of Diamonds State Park in Arkansas. He claimed there were $5 billion worth of diamonds there, but in 1996 it was halted as it was found to be not worth mining.
Boulle was chairman, founder and CEO as well as a major shareholder of Diamond Fields which commenced trading on the Vancouver Stock Exchange on 6 April 1993 and, in late 1994, discovered nickel, copper and cobalt ore bodies at Voisey's Bay Mine in Labrador, Canada. The Voisey's Bay Mine deposit was estimated to contain 141 million tonnes at 1.6% nickel. Boulle and Robert Friedland worked together in Diamond Fields and, in 1996, the Voisey's Bay Mine Project was purchased by Inco for CND$4.3 billion. Boulle's next company, Diamond Fields International is involved in sea floor mining with interests in mining deposits around the world.
Boulle Mining Group Luxembourg was the largest shareholder in World Titanium Resources, the Australian Securities Exchange listed discoverers and owners of the Toliara Sands titanium deposit in Madagascar. World Titanium Resources was delisted from ASX on 30 January 2017 and is now privately owned as World Titane Holdings Limited. In December 2017, Base Resources signed a $75m agreement to acquire an 85% interest in the Toliara Sands project in Madagascar from World Titane Holdings Limited. Together with the Government of Mauritius, Boulle is one of the three controlling shareholders of Omnicane, a publicly listed company on the Stock Exchange of Mauritius. Omnicane owns sugarcane plantations in Mauritius and produces refined sugar. Omnicane also generates around 30% of the island's electricity for the Grid and 40% of the country's renewable bagasse-based energy. In December 2014, Boulle's company Tendyne Holdings Inc. announced the first successful human Mitral Valve implant at the Royal Brompton Hospital in London, England. In September 2015, an agreement was reached with Abbott Laboratories to acquire Tendyne Holdings Inc.for a total consideration of US$400 million, excluding Abbott Laboratories’ existing 10% of the company. In February 2020, the Tendyne transcatheter mitral heart valve implant which Boulle's Tendyne Holdings Inc. had developed received CE Mark approval from the European Union and became the world's first commercially available solution for Mitral Valve Replacement Technology.
Controversy
Boulle has been accused of profiting from Africa's misery and manipulating African governments, with one of his companies, America Mineral Fields included in a draft of a UN report on the illegal exploitation of resources from the Democratic Republic of the Congo. The United Nations Report S/2003/1027 sent by United Nations Secretary General Kofi A. Annan to the Security Council on 23 October 2003 later removed the names of several companies, including America Mineral Fields.
Personal life
Boulle is a Mauritian citizen, and lives in Monaco. He is married and has two children.