Species: Native Copper⠀
Locality: Rocklands mine, Cloncurry, Queensland, Australia⠀
Dimensions: 11.5 x 4 x 1.7 cm.⠀
By now, native copper from the Rocklands mine in a remote part of Queensland, Australia has become well-known to most mineral collectors, due to the large quantity of material coming on to the market starting around 2017 when a major European dealer got the rights to do a specimen mining project at this relatively new (circa 2012) high-grade copper mine. While most copper recovered from the Rocklands mine from 2017 to now has been characterized by spongy to finely filligreed masses of small twinned copper crystals, early in the mine’s operation, a small number of superb to world-class crystallized copper specimens were found. Unfortunately the scarcity of these specimens on the market is mainly due to the strict no-collecting policy of the mine operator, CUDECO, during this period. However, in a testament to the amazing complexity of our globalized economy and mineral specimen business, I was recently able to acquire a small lot of some good to excellent crystallized copper specimens which were ‘rescued’ from scrap processing overseas by mineral dealers and collectors. These specimens feature well-formed spinel twins (exceptionally up to 18 cm!) as well as smaller modified dodecahedral and possibly octahedral copper crystals, often in aesthetic aggregates without matrix and with pleasing patinas ranging from red to brown to lustrous silvery-bronze. They reinforce that while relatively few in number, the best copper specimens found at the Rocklands mine are globally-significant for the species, and will be remembered as “Australian classics’ in time.
This excellent cabinet-size specimen consists of an aesthetic open network of sharp spinel-twinned copper crystals without matrix. The patina is a nice medium brown color, and the piece displays wonderfully on both sides. Reminiscent of the fine crystallized coppers found at the Ray mine in Arizona in the 1970’s and 80’s, or in Kazakhstan in later decades, this is a fine copper specimen from a contemporary classic locality for the species. The spinel twins are up to ~3 cm and quite good for the locality. A great example of the finest crystallized coppers produced at the Rocklands mine during a brief window at the start of the mine’s life. Annette Slade photo.