Lead manganese oxide mineral
(repeating unit)Pb(Mn4+6Mn3+2)O16 | | IMA symbol | Cor[1] |
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| Strunz classification | 4/D.08-70 |
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| Dana classification | 7.9.1.4 |
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| Crystal system | monoclinic |
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| Space group | I2/m |
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| Unit cell | a = 9.938, b = 2.8678, c = 9.834, Z = 1; β = 90.39° V = 280.26 |
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| Identification |
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| Formula mass | 933.55 |
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| Colour | dark grey to black |
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| Crystal habit | botryoidal; fibrous |
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| Mohs scale hardness | 4.5–5 |
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| Luster | submetallic |
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| Streak | brownish black |
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| Diaphaneity | opaque |
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| Density | 5.44 |
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| Refractive index | 2.72? |
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| Pleochroism | brown-grey |
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| Common impurities | Fe, Al |
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Coronadite is the lead endmember of the hollandite group, a family of tectomanganates with a 2 × 2 tunnel structure. The mineral was named after Francisco Vasquez de Coronado who was an explorer of southwest US. The name was made up by Waldemar Lindgren in 1905.[2]
References
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ "Coronadite Mineral Data". webmineral.com.
Polyhedral representation of the 2 × 2 tunnel structure of coronadite. The black atoms represent Pb.
