Olmiite: The mineral olmiite information and pictures

About

Olmiite is a relatively new mineral, only being officially named as a new species by the IMA in 2006. To date, it is found only in the Kalahari Manganese Field of South Africa. It is unusual for a newly discovered mineral to form is such large and excellent examples, with many well-formed and highly aesthetic examples of this mineral.
Olmiite forms a solid solution series with the much rarer mineral Poldervaartite. Many specimens that had been labelled as Poldervaartite have in fact been Olmiite upon analysis. Olmiite is named after Filippo Olmi, an Italian mineralogist from Florence, Italy.

Crystal Forms & Aggregates

In radiating spheres, as botryoidal, acicular, and wheat sheaf crystal groups, in groups of ball-shaped aggregates, and in stacked crystal plates. Individual pyramidal crystals are uncommon.

Other ID Marks

May be fluorescent red in shortwave ultraviolet light.

Striking Features

Color, crystal habits, and locality

Environment

In manganese-rich hydrothermal replacement deposits.

Uses

Well formed Olmiite examples with good color and form are highly valued by mineral collectors.

Noteworthy Localities

Olmiite has only been found in the Kalahari Manganese Field of South Africa, where it has been found both at the N'Chwaning Mines in Kuruman and the Wessels Mine in Hotazel.