Mineral - Aeschynite-(Ce)
Aeschynite-(Ce)
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
radioactive
Formula
Ce(TiNb)O₆
Unit Cell
a=7.54 b=10.96 c=5.40 Z=4
Physical Properties
Hardness
5 - 6
Streak
brown
Density
Cleavage
Indistinct after (100)
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
blackbrown
Birefringence
Luster
Metallic,
Pearly,
Resinous,
Waxy
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pmna (53)
Habit
coarse, massive, prismatic, columnar, tabular
Formation
As a primary accessory mineral, formed by crystallization from highly differentiated magmatic residual melts enriched in incompatible elements or hydrothermal fluids, occurring predominantly in granitic pegmatites (NYF-type) as well as in alkaline igneous rocks (e.g. nepheline syenites) and carbonatites
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Aeschynite-(Ce), Aeschynite, Aeschynite-Ce, Cerium-Aeschynite
Composition
Elements
Mass
Nb₂O₅
29.64
TiO₂
21.81
SnO₂
0.18
ThO₂
15.75
(Y,Er)₂O₃
1.12
(La,Dy)₂O₃
5.60
Ce₂O₃
18.49
FeO
3.17
CaO
2.75
LOI
1.07
Russia (Palache et al. 1952)
Groups and Members
Aeschynite-Group
Name and first discovery : Named after the Greek word "aeschyne" for "shame," due to chemists' failed attempts to separate the titanium from the zirconium in aeschynite (Ce). Discovered in Russia in 1830.
Chemistry :
Synonyms : Eschynite
Varieties : Alumolyndochite, Calciolyndochite
Abbreviation : Aes-Ce
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.