Chemistry:Aeschynite-(Ce)

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Short description: Oxide mineral
Aeschynite-(Ce)
General
CategoryOxide minerals
Formula
(repeating unit)
(Ce,Ca,Fe,Th)(Ti,Nb)
2
(O,OH)
6
Strunz classification4.DF.05
Dana classification08.03.06.01
Crystal systemOrthorhombic
Dipyramidal class
Space groupH-M symbol: (2/m 2/m 2/m)
Space group: Pmnb
Unit cella = 11.08, b = 7.56
c = 5.37 [Å]; Z = 4
Identification
Formula mass305.70 g/mol
ColorBrown, light brown, brownish black, yellow, black
Crystal habitAcicular, massive
CleavageNone
FractureBrittle - conchoidal
TenacityBrittle
Mohs scale hardness5 - 6
|re|er}}Adamantine, resinous to waxy, sub-metallic; dull when altered
StreakNearly black to brown
DiaphaneityTransparent to translucent
Specific gravity4.52
Density5.19
Optical propertiesIsotropic when metamict
Refractive index2.26
Other characteristicsRadioactive.svg Radioactive
References[1][2][3][4][5]

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.

See also

References