Mineral Type - Rhodonite
Pyroxmangite of MnSiO3 composition is the high-pressure, low-temperature polymorph with respect to rhodonite of the same composition (Maresch & Mottana, 1976). There is also an unnamed α phase - UM1975-18-SiO:Mn - recognized in limestones from the Polish Tatra Mts.
Transparency: Transparent, Translucent. Somewhat pearly on cleavage
Colour: Red, pink, brownish-red, grey
Streak: White
Hardness: 5½ - 6½ on Mohs scale. 5.5 parallel to [001], 7 parallel to [100]
Cleavage: Perfect. Perfect on {110} & {110}. Good on {001}br/> Fracture: Irregular/Uneven, Conchoidal
Density: 3.57 - 3.76 g/cm3 (Measured) 3.726 g/cm3 (Calculated)
Elements listed: Mn, O, Si
Common Impurities: Al, Ca, Fe. Zn
Class (H-M): 1 - Pinacoidal
Morphology: Crystals rough, typically tabular
Twinning: Lamellar, with {010} as composition plane. Non-standard space-group setting C-1.
Name
Named in 1819 by Christoph Friedrich Jasche from the Greek ρόδον, "rose", referring to its color.Physical Properties
Lustre: Vitreous, PearlyTransparency: Transparent, Translucent. Somewhat pearly on cleavage
Colour: Red, pink, brownish-red, grey
Streak: White
Hardness: 5½ - 6½ on Mohs scale. 5.5 parallel to [001], 7 parallel to [100]
Cleavage: Perfect. Perfect on {110} & {110}. Good on {001}br/> Fracture: Irregular/Uneven, Conchoidal
Density: 3.57 - 3.76 g/cm3 (Measured) 3.726 g/cm3 (Calculated)
Chemical Properties
Formula: CaMn3Mn(Si5O15)Elements listed: Mn, O, Si
Common Impurities: Al, Ca, Fe. Zn
Crystallography
Crystal System: TriclinicClass (H-M): 1 - Pinacoidal
Morphology: Crystals rough, typically tabular
Twinning: Lamellar, with {010} as composition plane. Non-standard space-group setting C-1.