Hibonite, 1.6 cm (0.63 in) sharp and lustrous crystal from Esiva eluvials, Maromby Commune, Amboasary District, Anosy (Fort Dauphin) Region, Tuléar (Toliara) Province, Madagascar
General
Category
Oxide minerals
Formula (repeating unit)
(Ca,Ce)(Al,Ti,Mg)12O19
IMA symbol
Hbn[1]
Strunz classification
4.CC.45
Crystal system
Hexagonal
Crystal class
Dihexagonal dipyramidal (6/mmm)
H-M symbol: (6/m 2/m 2/m)
Space group
P63/mmc
Unit cell
a = 5.56, c = 21.89 [Å]; Z = 2
Identification
Color
Brownish black to black; reddish brown in thin fragments; blue in meteorite occurrence
Crystal habit
Prismatic platy to steep pyramidal crystals
Cleavage
{0001} good, {1010} parting
Fracture
Subconchoidal
Mohs scale hardness
7+1⁄2–8
Luster
Vitreous
Streak
reddish brown
Diaphaneity
Semitransparent
Specific gravity
3.84
Optical properties
Uniaxial (-)
Refractive index
nω = 1.807(2), nε = 1.79(1)
Pleochroism
O = brownish gray; E = gray
References
[2][3]
Hibonite is a mineral with the chemical formula (Ca,Ce)(Al,Ti,Mg)12O19, occurring in various colours, with a hardness of 7.5–8.0 and a hexagonal crystal structure. It is rare, but is found in high-grade metamorphic rocks on Madagascar. Some presolar grains in primitive meteorites consist of hibonite. Hibonite also is a common mineral in the Ca-Al-rich inclusions found in some chondritic meteorites. Hibonite is closely related to hibonite-Fe (IMA 2009-027, (Fe,Mg)Al12O19)) an alteration mineral from the Allende meteorite.[4] Hibonites were among the first minerals to form as the disk of gas and dust swirling around the young sun cooled.[5]
A very rare gem, hibonite was discovered in 1953 in Madagascar by Paul Hibon, a French prospector.[6]
Hibonite is a mineral with the chemical formula (Ca,Ce)(Al,Ti,Mg)12O19, occurring in various colours, with a hardness of 7.5–8.0 and a hexagonal crystal...
heated. Hibonite was discovered in 1956 in Madagascar. It was named after the discoverer, French geologist Paul Hibon. Gem quality hibonite has been...
) Monocalcium hexa-aluminate, CaO·6Al2O3 (CA6) (occurring in nature as hibonite, a representative of magnetoplumbite group) In addition, other phases include:...
mayenite and larnite. In meteorites it occurs with perovskite, melilite, hibonite, spinel and calcium rich pyroxene. Glossary of meteoritics Warr, L.N. (2021)...
of CaAl12O19, SrAl12O19, La2/3+δAl12–δO19, and CaAl10NiTiO19 with the hibonite structure; indications of an unusual type of ferroelectricity". Zeitschrift...
form. This was followed by graphite, oxides (rutile, corundum, spinel, hibonite), carbides (moissanite), nitrides (osbornite and silicon nitride) and silicates...
MEMBER OF THE MAGNETOPLUMBITE GROUP AND THE CRYSTAL CHEMISTRY OF MAGNETOPLUMBITE AND HIBONITE" (PDF). The Canadian Mineralogist. 34: 1287–1297. 1996. v t e...
& Planetary Science, vol. 34, Supplement, p.A84. Isotopic Records in Hibonites from CM Meteorites. Marhas, K. K., Sinha, N., Davis, A. M., & Goswami...
magnetoplumbite group, and the crystal chemistry of magnetoplumbite and hibonite. The Canadian Mineralogist 34, 1287-1297 Chukanov, Nikita V.; Aksenov,...
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