Kimberlite and of those just over 30 have been economic enough to diamond mine. The deposits occurring at Kimberley, South Africa, were the first recognized and the source of the name. The Kimberley diamonds were originally found in weathered kimberlite, which was colored yellow by limonite, and so was called "yellow ground". Deeper workings encountered less altered rock, serpentinized kimberlite, which miners call "blue ground". See also Mir Mine and Udachnaya pipe, both in the Sakha Republic, Siberia. The blue and yellow ground were both prolific producers of diamonds. After the yellow ground had been exhausted, miners in the late 19th
Volcanic Rock (album) Music CD reissue Volcanic Rock (album) Volcanic Rock is the second studio album by Australian proto-heavy metal band Buffalo, recorded and originally released in 1973 on the Vertigo label. The album was stylistically a much harder, heavier and rawer release than its predecessor ("Dead Forever...") – marking a move away from the band's previous progressive rock influences, although retaining a psychedelic element to their sound. "Volcanic Rock" had been recorded effectively as a live-in-the-studio effort, with only vocal and additional guitar overdubs added later during the recording sessions. The album courted controversy with its cover artwork upon its release. Illustrated