Aeschynite-(Ce) | |
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General | |
Category | Oxide minerals |
Formula (repeating unit) | (Ce,Ca,Fe,Th)(Ti,Nb)2(O,OH)6 |
IMA symbol | Aes-Ce[1] |
Strunz classification | 4.DF.05 |
Dana classification | 08.03.06.01 |
Crystal system | Orthorhombic Dipyramidal class |
Space group | H-M symbol: (2/m 2/m 2/m) Space group: Pmnb |
Unit cell | a = 11.08, b = 7.56 c = 5.37 [Å]; Z = 4 |
Identification | |
Formula mass | 305.70 g/mol |
Color | Brown, light brown, brownish black, yellow, black |
Crystal habit | Acicular, massive |
Cleavage | None |
Fracture | Brittle - conchoidal |
Tenacity | Brittle |
Mohs scale hardness | 5 - 6 |
Luster | Adamantine, resinous to waxy, sub-metallic; dull when altered |
Streak | Nearly black to brown |
Diaphaneity | Transparent to translucent |
Specific gravity | 4.52 |
Density | 5.19 |
Optical properties | Isotropic when metamict |
Refractive index | 2.26 |
Other characteristics | Radioactive |
References | [2][3][4][5][6] |
Aeschynite-(Ce) (or Aschynite, Eschinite, Eschynite) is a rare earth mineral of cerium, calcium, iron, thorium, titanium, niobium, oxygen, and hydrogen with chemical formula (Ce,Ca,Fe,Th)(Ti,Nb)2(O,OH)6. Its name comes from the Greek word αισχύνη ("aeschyne") for "shame" because early chemists had difficulty with separations of titanium from zirconium.[7]
The "-(Ce)" means it has more cerium than the yttrium variety aeschynite-(Y). Its Mohs scale rating is 5–6.
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