Orlymanite Locality: N'Chwaning II Mine, N'Chwaning Mines, Kuruman , Kalahari manganese fields, Northern Cape Province , South Africa ( Locality at mindat.org ) Brown balls and crust of Orlymanite. Field of view 16 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Orlymanite
Orlymanite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₄Mn²⁺₃Si₈O₂₀(OH)₆·2H₂O.
It crystallizes in the hexagonal crystal system. It is a member of the Gyrolite structural group.
Key properties: Mohs hardness 4–5; specific gravity 2.7–2.8; Light brown streak; Vitreous luster; optically uniaxial.
IMA symbol Orl, IMA status: approved, named in 1988.
Apparently as a vein mineral in a manganese ore body.
It is found associated with Inesite, hematite, calcite.
In honor of Orlando Lyman (?{1986), founder of the Lyman House Memorial Museum in Hilo, Hawaii, USA.