Is a Manganese oxide with formula (Mn+2)(Mn+3)2O 4 and hardness 5.5.
Rarely see as facet gem, mostly is known as mineral collector’s.
Opaque with dark color and submetallic to metallic luster.
This stone comes from the Kalahari Manganese Fields, north of Kuruman, Otazei,Orange free State, South Africa.
Size: 12x10.2x7.5 mm.