N'Chwaning I Mine, Kuruman, Kalahari manganese fields, Northern Cape Province, South Africa

6.8 x 5.7 x 4.2 cm
The largest Shigaite crystal is 4 mm across.
2.7 x 2.2 x 1.7 in

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Shigaite: Mn₆Al₃(OH)₁₈[Na(H₂O)₆](SO₄)₂·6H₂O , Caryopilite: Mn²⁺₃Si₂O₅(OH)₄

Shigaite is a rare manganese, aluminum sulfate. There are actually several crystals of Shigaite on this specimen, but only one really stands out; the others being smaller or tucked away in recessed areas. The Shigaite crystals are wafer thin and an attractive reddish, golden brown color. The surface of the specimen is covered with Rhodochrosite and Caryopilite. The Rhodochrosite is present as reddish brown, small, thin, elongated, well formed, transparent crystals with a high, sparkly luster. The Caryopilite is light brown in color and has formed spherical aggregates in places. Also present are thin, rectangular Barite crystals which range in color from light gray to nearly black.

Condition: Good

Flaws: The largest Shigaite crystal has a small internal cleave below the surface of one of the corners. On the edges of the specimen, there are a few small areas of damage.

This mineral is also found in the following galleries: Minerals From Africa | Sulfates | Phyllosilicates | Carbonates | Rare Minerals | Minerals Priced Between 200 and 299 Dollars