This 500-franc certificate N°2,592 belongs to the Société Française du Diamant Noir, known as Taverdon, issued in Paris on 30 November 1883. Black diamond, or carbonado, is a variety of polycrystalline greyish or black diamond exploited principally in Brazil and Central Africa, used for its abrasive properties in industry (drills, grindstones, drill bits). In the 19th century, before the ornamental properties of black diamond were exploited in jewellery, its use was primarily industrial. The name "Taverdon" may be a reference to the famous gem merchant Jean-Baptiste Tavernier (17th century)