Manganilvaite
Manganilvaite is an IMA-recognized mineral species in the silicate class, with the chemical formula CaFe²⁺Fe³⁺Mn²⁺(Si₂O₇)O(OH).
It crystallizes in the monoclinic crystal system (space group P2_1/a). It is a member of the Ilvaite structural group.
Key properties: Mohs hardness 5.5–6; specific gravity 3.92; Black to brownish black streak; Vitreous luster.
IMA symbol Mlv, IMA status: approved, named in 2002.
From the retrograde, hydrothermal alteration of manganiferous minerals in Pb-Zn-(Mn) contact metamorphic rocks (skarns).
It is found associated with Bustamite, hedenbergite-johannsenite, manganoan ferro-actinolite, rhodonite, rhodochrosite, manganoan calcite and chlorite, andradite, sphalerite, galena.
As the Mn-analogue of ilvaite.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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