Mineral - Aeschynite-(Y)
Aeschynite-(Y)
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
none
Formula
Y(TiNb)O₆
Unit Cell
a=7.45 b=11.00 c=5.18 Z=4
Physical Properties
Hardness
5 - 6
Streak
whiteredyellowyellow red
Density
Heavy (3,5-6)
Cleavage
Perfect after (100), (010) and (001)
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
blackbrownorangeyellowbrown black
Birefringence
0.220
Luster
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
blocky, prismatic, prismatic, 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
Rather rare
Synonyms
Aeschynit-(Y), Aeschynit, Aeschynit-Y, Yttrium-Aeschynit
Composition
Elements
Mass
Nb₂O₅
17.99
Ta₂O₅
0.89
SiO₂
0.38
TiO₂
32.91
SnO₂
0.12
ThO₂
7.69
ZrO₂
<0.01
UO₂
4.01
Al₂O₃
<0.01
(Y,Er)₂O₃
28.76
Ce₂O₃
1.97
FeO
1.48
MnO
0.27
PbO
0.06
MgO
0.04
CaO
1.02
Na₂O
0.22
K₂O
0.19
H₂O
1.88
Norway (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. Discovered in Norway in 1906.
Chemistry :
Synonyms : Blomstrandine, Blomstrandinite, Priorite, Taiyite
Varieties :
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.