Effenbergerite
Effenbergerite is the natural occurrence of the color Han blue. It was first found in the Wessels mine, Kalahari Manganese Field, South Africa.
Effenbergerite was approved as a valid mineral species by the IMA in 1993.
Effenberergite has the chemical formula.
The mineral was named after Dr. Herta S. Effenberger, a mineralogist and crystallographer at the University of Vienna.