Olmiite

N'Chwaning II Mine, N'Chwaning mining area, Kuruman, Kalahari manganese field (KMF), Northern Cape Province  South Africa (10/2008)

Specimen size: 9.2 × 5.8 × 3 cm = 3.62” × 2.28” × 1.18”
Main crystal size: 2.8 × 2.1 cm = 1.10” × 0.83”