Early career Boulle worked for the
De Beers Diamond Trading Company (DTC) for ten years, in
Zaire,
Sierra Leone and
Antwerp,
Belgium. He then established Boulle Inc. in Dallas, Texas. He began exploring for diamonds in 1984, first in
Minnesota and 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.
Diamond Fields and Voisey's Bay Mine Boulle was chairman, founder and CEO, as well as a major shareholder, of
Diamond Fields Resources (
TSE:DFR), which commenced trading on the
Vancouver Stock Exchange on 6 April 1993. In late 1994, prospectors with Archean Resources discovered nickel, copper and cobalt
ore bodies at
Voisey's Bay Mine in Labrador, Canada. The deposit was estimated to contain 141 million tonnes at 1.6% nickel. Boulle and
Robert Friedland worked together in the vehicle, and in 1996 the project was purchased by
Inco for C$4.3 billion. Boulle's next company, Diamond Fields International, is involved in seafloor mining with interests in deposits around the world.
American Mineral Fields His Boulle Mining Group is headquartered in
Luxembourg and in 1995 founded American Mineral Fields (later renamed
Adastra Minerals), listed on the
London Stock Exchange's
Alternative Investment Market and the
Toronto Stock Exchange. Adastra Minerals developed mining projects in the
Democratic Republic of the Congo and a joint venture with the Congolese government to re-treat the
Kolwezi tailings project. Adastra Minerals was purchased in August 2006 by
First Quantum Minerals, a mining company then with dual listings on the Toronto Stock Exchange and the London Stock Exchange (until 31 May 2016). In 2001, Boulle acquired the Sierra Rutile Project (a producer of natural
rutile) and the Sierra Minerals SML Bauxite Mine in Sierra Leone, West Africa, which became part of
Titanium Resources Group, taken public on the London Stock Exchange's Alternative Investment Market in August 2005.
Greenland Gold Resources and Greenland Anorthosite His mining group's subsidiary company, Greenland Gold Resources Ltd, is exploring in
Greenland for nickel, copper, cobalt,
platinum group elements, titanium and
graphite. His other Greenland company, Greenland Anorthosite, has attracted co-investment from the Danish national investment fund Vækstfonden, the Greenland state investment company Greenland Venture A/S and the Greenlandic pension fund SISA.
Tendyne Holdings In December 2014, Boulle's company Tendyne Holdings Inc. announced the first successful human
mitral valve implant at the
Royal Brompton Hospital in London. In September 2015, an agreement was reached with
Abbott Laboratories to acquire Tendyne Holdings Inc. for a total consideration of US$400 million ($250 million plus regulatory-based milestones), excluding Abbott Laboratories' existing 10% of the company. In February 2020, the Tendyne transcatheter mitral
heart valve implant developed by Tendyne Holdings received CE Mark approval from the European Union, becoming the first commercially available mitral valve replacement technology. In May 2025, the Tendyne transcatheter mitral heart valve implant received FDA approval in the United States for mitral valve replacement without open-heart surgery.
Trained Therapeutix Discovery Boulle's company Trained Therapeutix Discovery and its co-founders Professor
Mihai Netea and Leo Joosten have revealed that innate immune systems have adaptive characteristics. This de facto innate immune memory was coined "
trained immunity" by Netea. In 2022, Boulle and the Spanish Society of Immunology (Sociedad Española de Inmunología, or SEI) founded the Boulle-SEI International Awards to acknowledge and support the work of the healthcare and life sciences community.
World Titanium Resource 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 the ASX on 30 January 2017 and is now privately owned as World Titane Holdings Limited. In December 2017, Base Resources signed a $75 million agreement to acquire an 85% interest in the Toliara Sands project in Madagascar from World Titane Holdings Limited.
Omnicane Together with the National Pension Fund and the Sugar Investment Trust of
Mauritius, Boulle is one of the major shareholders of
Omnicane, a publicly listed company on the
Stock Exchange of Mauritius. Omnicane owns
sugarcane plantations in Mauritius and produces refined sugar, in addition to providing some electricity to the island.
Raphael Fishing Company Boulle is the majority shareholder in the
Raphael Fishing Company, a 95-year-old company which made legal history in 2008 when it was adjudged a
Permanent Grant by the
United Kingdom Privy Council on the Thirteen Islands of
St Brandon (
Cargados Carajos). The permanent grant was confirmed based on an earlier permanent lease (
999-year lease) dating back to 1901.
Other work In November 2012, entertainment industry media outlet
Variety reported that the Jean Boulle Group owned the adaptation rights for the 1969 counterculture classic film
Easy Rider, originally released by
Columbia Pictures, and were part of a consortium including Maurice Fadida's Kodiak Pictures and Defiant Studios' Eric B. Fleischman. Boulle is Vice Chairman of the Board of Directors of the US-based
Corporate Council on Africa. In 1999 and 2000, Boulle was a prime mover in the creation of the
African Growth and Opportunity Act (AGOA), the primary governing US law on trade with Africa. AGOA provides duty-free treatment to goods of designated sub-Saharan African countries and includes Mauritius. The programme promotes economic growth through good governance and free markets, covering both textile and non-textile goods, and was most recently reauthorised to 30 September 2025. In 2002, Boulle sponsored and promoted Mauritius as a venue and helped to organise the Second US-SSA AGOA Forum on 13 January 2003. == Conservation ==