Abstract Gems & Gemology, Summer 2013, Volume 49, No. 2

The Ellendale Diamond Field: Exploration History, Discovery, Geology, and Mining

The Ellendale diamond field in West Kimberley is one of only three hard-rock diamond mine locations in Australia. Though not the first Australian diamond mine, Ellendale was the country’s first hard-rock deposit. It holds a special place in world diamond history as it led in November 1976 to the recognition of a new host-rock for diamond, olivine lamproite. Up until that time, commercial-sized diamonds were considered to be sourced only from kimberlite. The Ellendale lamproites are geologically very young, only 22 Ma (million of years) old. Within several years of the initial discovery, some 46 lamproite pipes were found at Ellendale. By 1980, 38 of these pipes had been assessed for their diamond content. 
More than two decades later, geologists from the Kimberley Diamond Company (KDC) recognized eluvial diamond enrichment over these pipes. After a lengthy legal battle, they wrested the Ellendale mining lease from the Ashton Joint Venture and commenced mining there in May 2002. Ellendale is recognized as a source of high-value fancy yellow diamonds. These high priced stones have been marketed through a special deal with Tiffany & Co since 2009. But the future of mining there is tenuous. Ellendale 4 was closed in 2009, and the high Australian dollar, combined with dwindling reserves, may jeopardize the survival of Ellendale 9.

Abstracted by Guy Lalous