Inesite Wessels Mine, Kalahari MN Fields, N. Cape Prov., S. Africa Small Cabinet, 6.6 x 3.7 x 2.4 cm © irocks

Chemical Formula: Ca2(Mn,Fe)7Si10O28(OH)2·5H2O
Locality: Banska Stiavnica, Czechoslovakia.
Name Origin: From the Greek ines – “flesh fibers.”

Inesite is not a common mineral in rock shops and in mineral displays. However it can form attractive pink or rose colored specimens that are sought after by mineral collectors. The commonly seen prismatic crystals have a slanted or “chisel-shaped” termination. At first glance the shorter crystals may be mistaken for rhombohedrons which have six equally slanted faces. Inesite will show only one steeply slanted face, while the other faces have a much less inclined slant. This is important for identification because the pink to rose colored mineral rhodochrosite forms rhombohedrons. Another similar looking mineral is the silicate rhodonite. Fortunately rhodonite lacks any steeply inclined faces and is normally blocky, not prismatic.

Physical Properties

Cleavage: {010} Perfect, {100} Good
Color: Brown, Brown, Pink, Orange.
Density: 3.029 – 3.1, Average = 3.06
Diaphaneity: Translucent
Fracture: Brittle – Uneven – Very brittle fracture producing uneven fragments.
Hardness: 6 – Orthoclase
Luminescence: Non-fluorescent.
Luster: Vitreous (Glassy)
Streak: white


Inesite Locality: Fengjiashan Mine (Daye mine), Edong Mining District, Daye Co., Huangshi Prefecture, Hubei Province, China Specimen Size: 4.7 x 4.2 x 3.4 cm (miniature) © minclassics
Inesite Kalahari manganese fields, Northern Cape Province, South Africa Size: 13.0 x 8.0 x 4.0 cm (cabinet) © danweinrich
Inesite Hale Creek Mine, Trinity County, California Cabinet, 10.9 x 6.8 x 6.0 cm © irocks
Inesite Wessels Mine, Kalahari manganese fields, Northern Cape Province, South Africa Miniature, 3.6 x 2.9 x 2.6 cm © irocks
Fengjiashan Mine (Daye copper mine), Daye Co., Huangshi Prefecture, Hubei Province, China © Elmar Lackner