The Ellendale Diamond Field, is one of only three hard-rock diamond mine locations in Australia. Diamonds were first discovered at Ellendale in an olivine lamproite pipe in November 1976. Although not the first diamond mine to start in Australia, Ellendale was the first hard-rock deposit to be found, and this provided the ongoing stimulus. Within several years of the initial discovery, some 46 Miocene-aged (~22 Ma) lamproite pipes were found within the Ellendale Lamproite Field and by 1980 thirty-eight of these pipes had been assessed for their diamond content. The highest grade pipes, Ellendale 4, Ellendale 4a, and Ellendale 9, contained diamond grades of 5-14 carats per hundred tonnes (cpht), but were deemed sub-economic at the time. Over two decades later, Kimberley Diamond Company (KDC) geologists recognised eluvial diamond enrichment over these pipes and commenced mining at Ellendale 9 pipe in May 2002.