Kostovite (IMA symbol: Ktv) is a rare orthorhombic-pyramidal gray white telluride mineral containing copper and gold with chemical formula AuCuTe4.

[2][3][4] It was discovered by Bulgarian mineralogist Georgi Ivanov Terziev, who named it in honor of his professor Ivan Kostov (Иван Костов) (1913–2004).

[7][8] In 1965 kostovite was approved as a new species by the International Mineralogical Association.

[9] The type locality is Chelopech copper ore deposit, Bulgaria.

[10] Small deposits have also been found in Kochbulak (Eastern Uzbekistan), Commoner mine (Zimbabwe), Kamchatka (Russian Far East), Ashanti (Ghana), Buckeye Gulch (Leadville, Colorado, US), Bisbee (Arizona, US),[11] Kutemajärvi (Finland), Coranda-Hondol (Romania), Glava (Sweden), Bereznjakovskoje (Southern Urals, Russia), Moctezuma (Sonora, Mexico), Panormos Bay (Tinos Island, Greece), Guilaizhuang Mine, Tongshi complex (Linyi Prefecture, Shandong Province, China), Kalgoorlie-Boulder City, (Goldfields-Esperance region, Western Australia, Australia).