Originally described by Dr Peter Elliott (et al) a mineralogy researcher from the University of Adelaide after detailed analysis of a sample given to him by the Commonwealth Scientific and Industrial Research Organisation. Putnisite was was approved by the IMA in 2012, and named after for after Australian mineralogists Dr Andrew and Dr Christine Putnis.
This strongly purple mineral with tiny (orthorhombic) crystals no more than 0.5mm in size was first seen at Polar Bear Peninsula, Lake Cowan, Western Australia, but has also since been identified at Armstrong Mine, Widgiemooltha, Western Australia.
It is the chemistry that makes this a special mineral boasting 2 unique features.
With a formula SrCa4Cr3+8(CO3)8SO4(OH)16 · 23H2O, Putnisite is
- the first mineral combining strontium and chromium
- the first mineral with strontium bearing carbonate-sulphate chemistry
Quoting Dr Elliott “Most minerals belong to a family or 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.
“Nature seems to be far cleverer at dreaming up new chemicals than any researcher in a laboratory.”
To me this is an interesting counterpoint to the "big data" work on predicting minerals by chemistry currently being undertaken.
Of course we look forward to hearing about and seeing new minerals however they are discovered!