-69- Sovereign Hill Quartz Mining Company/ Poppet Head By the early 1860's, surface gold was becoming harder to find, so miners began extracting gold from buried quartz reefs. Sovereign Hill's Quartz Mine illustrates quartz mining on the Ballarat East goldfield from 1860 to 1916. The Mine is made up of two sections; surface installations and underground displays, of which there are guided tours. The imposing Poppet Head is a well known icon of Sovereign Hill.