Specimen #1365

Name: Olmiite with calcite

Type: Mineral

Locality: N'Chwaning II Mine, Kalahari manganese fields, Northern Cape Province, South Africa

Favorite? N

Fluorescent? N

Size: 16.3 x 12.8 x 6.1 cm

Weight: 1709

Acquired: 2009-04-30

Source: Arkenstone Auction

Label: Y

Comment: A SUPER showy and DRAMATIC, two-tiered, LARGE CABINET specimen is aesthetically sprinkled with ball-like clusters of lustrous, tan, sharply crystallized, orthorhombic olmiite crystals and RARE, single prism crystals of olmiite! The large cluster is 2.0 cm and the longest single crystal is 1.2 cm. A SUPER accent is the 1.1 cm, flattened, calcite twin! The layered hematite matrix gives the complimentary, ultra-sparkly, water-clear calcite crystal coating a distinct lavender tint. Many of the calcite crystals are doubly terminated. Olmiite is the manganese-dominant variant of poldervaartite and is found ONLY at the famous N’Chwaning II Mine,its type locality now. Olmiite was not named until 2007!

Minerals: Calcite (CaCO₃) Olmiite ( CaMn ₂⁺ [SiO ₃ (OH)](OH))

There are 2 pictures on file

M01365-01.jpg:

Olmiite with calcite, N'Chwaning II Mine, Kalahari manganese fields, Northern Cape Province, South Africa - 16.3 x 12.8 x 6.1 cm

M01365-02.jpg:

Olmiite with calcite, N'Chwaning II Mine, Kalahari manganese fields, Northern Cape Province, South Africa