Quartz

Quartz from the Red Dome Mine, Chillagoe, Queensland, Australia, measuring 98 × 74 × 40 mm and weighing 301 grams. A good, solid piece from the far north Queensland mining district around Chillagoe.

Quartz is silicon dioxide, SiO2, the reference mineral for hardness 7, and it crystallises as six-sided prisms capped by rhombohedral terminations. It grows in almost every geological setting, which is exactly why locality matters so much in collecting it. At Red Dome the mineralisation is a gold-copper skarn, formed where hot fluids from an intrusion reacted with surrounding limestone, and Quartz is one of the minerals that crystallised in that hydrothermal system.

Chillagoe has a long mining history, with copper, lead and silver worked from the late nineteenth century, and the district's limestone towers and caves are now a well-known landmark. Red Dome was a later open-pit gold-copper operation in the same district. This Quartz is recorded with both Down Under Minerals and the David Vince Collection, a documented link for a far north Queensland locality that is not often represented.