Specimen #695

Name: Ettringite

Type: Mineral

Locality: Wessels Mine (Wessel's Mine), Hotazel, Kalahari manganese fields, Northern Cape Province, South Africa

Favorite? N

Fluorescent? N

Size: 6.9 x 4.9 x 1.1 cm

Weight: 33

Acquired: 2008-06-05

Source: Arkenstone Auction

Label: Y

Comment: The rare mineral ettringite (Hydrated Calcium Aluminum Sulfate Hydroxide), closely related to sturmanite, is best-known in specimens from the Nchwaning locality. It forms as a precipitate from hydrothermal solutions. This is a plate of bright yellow, solid ettringite, crystallized on the surface with the typical nailhead-from crystals.

Minerals: Ettringite (Ca₆Al₂(SO₄)₃(OH)_{12 26}(H₂O))

There are 2 pictures on file

M00695-02.jpg:

Ettringite, Wessels Mine, Kalahari Manganese Fields, South Africa, 6.9 x 4.9 x 1.1 mm

M00695-03.jpg:

Ettringite, Wessels Mine, Kalahari Manganese Fields, South Africa