Though small amounts of turquoise were found in the Campbell shaft mine, as well as in stream beds in the Mule Mountains, the vast majority of Bisbee turquoise surfaced when the Phelps Dodge Corporation started open pit mining operations at the location now known as the Lavender Pit, especially the eastern side of the pit. Large amounts of a conglomerate rock bed needed to be removed before the copper ore located more deeply could be reached. This sedimentary conglomerate waste rock was the host for most of the turquoise, in both vein and nugget form.