3.1" Poldervaartite and Olmiite - N'Chwaning Mine, South Africa

This is an association of olmiite and poldervaartite on a manganese-rich matrix. The entire specimen measures 3.1" wide and was collected from the N'Chwaning Mine in the Kalahari Manganese Fields of Kuruman, Africa. Under shortwave UV, the crystals fluoresces a vibrant red-pink color.

Poldervaartite is a calcium and manganese-based mineral, which features Ca as the dominant molecule. This is notable from its chemical formula, (Ca2,Mn)[SiO3(OH)](OH). This is very similar to olmiite, a manganese-dominant mineral with the chemical formula CaMn[SiO3(OH)](OH). Both are found in association with each other in a few known locations in South Africa, most commonly throughout the Kalahari Manganese Fields.

Poldervaartite tends to consist of a peach color enshrouded in a transparent mineral sheath, while olmiite typically exhibits a deeper salmon color, with little to no transparency depending on the specimen's manganese content. Olmiite also displays a deep red fluorescent color when placed under short-wave UV-light, whereas poldervaartite does not fluoresce.
Poldervaartite & Olmiite
N'Chwaning Mine, Kalahari Manganese Fields, Kuruman, South Africa
3.1 x 1.5"