New purple-pink mineral discovered in Australia
A new purple-pink mineral that is unique in structure and composition among the world’s 4,000 known mineral species has been discovered at a mining site in Western Australia, according to a media release from The University of Adelaide in Australia.
A mining company discovered the new mineral—named putnisite for Australian mineralogists Andrew and Christine Putnis—during prospecting in a surface outcrop at Lake Cowan, north of Norseman in Western Australia.
Found on volcanic rock, putnisite occurs as tiny crystals, no more than approximately 0.02 inches (0.5 mm) in diameter, and appears as dark-pink spots on dark-green-and-white rock. Under a microscope, the new mineral appears as cube-like crystals. In addition, putnisite contains a very unusual combination of elements: calcium, carbon, chromium, hydrogen, oxygen, strontium and sulfur.
Dr. Peter Elliott, visiting research fellow at the University of Adelaide’s School of Earth and Environmental Sciences, as well as a research associate at the South Australian Museum, received the mineral for detailed analysis from the Commonwealth Scientific and Industrial Research Organization (CSIRO), Australia’s national science agency, which received it first for initial research.
“What defines a mineral is its chemistry and crystallography,” Elliott said in the release. “By x-raying a single crystal of mineral, you are able to determine its crystal structure. This, in conjunction with its chemical analysis, tells you everything you need to know about the mineral.
“Most minerals belong to a family or a small group of related minerals, or if they aren't related to other minerals, they often are to a synthetic compound, but putnisite is completely unique and unrelated to anything,” Elliott added. “Putnisite, a strontium calcium chromium sulfate carbonate, has both a unique chemical composition and a unique crystal structure.”
Dr. Elliott has researched 12 new Australian minerals in the past seven years, seven of which he found himself. Two of these new minerals were discovered in South Australia—domerockite and hylbrownite—named respectively after Dome Rock, where the mineral was first found, and Henry Yorke Lyle Brown, government geologist of South Australia from 1882-1912.
It has yet to be determined if putnisite will have any practical use. As for its potential use in jewelry fabrication, according to Dr. Elliott, putnisite is very difficult to polish because it’s quite soft and brittle; however, he understands that some soft minerals can be cut and polished for jewelry.
A putnisite crystal approximately 0.4 mm in size from the Armstrong Mine, Widgiemooltha, Western Australia.
Image by Dr. Peter Elliott.