Mineral - Avdeevite
Avdeevite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
NaAl₄(Be₅Li)(Si₆O₁₈)₂(H₂O)¹⁻₂
Unit Cell
a=9.23 c=9.26 Z=2
Physical Properties
Hardness
8
Streak
white
Density
Normal (2-3,5)
Cleavage
Imperfect after {001}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
whiteredpink
Birefringence
0.007
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
hexagonal
Point Group
dihexagonal-dipyramidal - 6/m 2/m 2/m
Space Group
P6 3 /mmc (194)
Habit
coarse, granular, massive, acicular, prismatic, radial
Formation
Magmatic, in pegmatites
Paragenesis
Twinning
Rarity
Rare
Synonyms
Avdeevite
Composition
Elements
Mass
SiO₂
61.06
Al₂O₃
17.40
BeO
8.58
Na₂O
1.77
K₂O
0.09
Cs₂O
6.44
Rb₂O
1.38
Li₂O
2.51
H₂O
0.42
Myanmar (Agakhanov et al. 2021)
Groups and Members
Beryl-Group
Name and first discovery: Named after the Russian chemist Ivan Vasil'evich Avdeev (1818-1865). First described in 2018.
Chemism:
Synonyms:
Varieties:
Abbreviation: Avd
Famous locations
(TL) Type locality (analysis) Chemical element distribution, see above
(TL) (analysis) Palelni Mine, Khetchel Village, Shan State, Myanmar
Literature
Agakhanov, A. A., Stepanenko, D. A., Zubkova, N. V., Pautov, L. A., Pekov, I. V., Kasatkin, A. V., ... & Pushcharovsky, D. Y. (2021). Avdeevite, a Na-dominant alkali beryl: Determination as valid mineral species and new data. Geologyof Ore Deposits, 63(7), 654-667.