Calcite (variety Mn-bearing calcite) with Manganite

N'Chwaning I Mine, N'Chwaning mining area, Kuruman, Kalahari manganese field (KMF), Northern Cape Province  South Africa

Specimen size: 9.8 × 6.3 × 5.5 cm = 3.86” × 2.48” × 2.17”