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 BaCuSi4O10.

The mineral was named after Dr. Herta S. Effenberger, a mineralogist and crystallographer at the University of Vienna.