IGI is the abbreviation for the International Gemological Institute, which certifies diamonds and other gemstones according to certain criteria and verifies the authenticity of the stones. The institute is headquartered in Antwerp and has additional locations in New York City, Tokyo and Toronto, for example. It was founded in 1975 and is, along with the GIA, one of the leading laboratories for the determination and evaluation of diamonds. The issued certificates provide information about the cut, the clarity, the colour and the weight in carat. Impartiality is guaranteed by a number of established principles of the institute. These include, for example, the equality of all clients and diamonds as well as objectivity. To this end, staff are trained and best methods are used. The IGI also continuously researches new methods and works closely with clients and professionals. In addition, it also offers diamond repairs.