Putnisite is the latest of 12 completely new Australian minerals characterised over the last few years by Dr Peter Elliott at the University of Adelaide with the help of AMMRF instruments and expertise. Three of the 12 minerals, including putnisite, are unlike any other natural or synthetic compounds yet described, each having a unique chemical composition and crystal structure.
Small crystals of putnisite, less than half a millimetre in size, have been found at two locations in Western Australia. They are translucent and very soft, as minerals go, ranging in colour from pale to dark purple, with cube-like crystals. Putnisite has a complex and unusual chemical composition, which can be described as strontium calcium chromium sulphate carbonate. The full analysis, including its equally complex crystal structure, has just been published in Mineralogical Magazine.
It isn’t clear yet if putnisite and the other new minerals will have practical applications but their unique and diverse structures provide a valuable knowledge base for materials scientists.