|
Click on a
letter above to view the list of gems. |
|
|
|
| Polylithionite
is named from the Greek word
poly meaning many or much, in allusion to its composition with a high LITHIum content.
| Discovered
in 1884; IMA
status:
Valid (pre-IMA; Grandfathered) |
|
Chemistry
|
|
|
Chemical
Formula: |
KLi2AlSi4O10
(F,OH)2
|
|
Potassium
Lithium Aluminum Silicate Fluoride |
Molecular
Weight: |
393.12 gm
|
Composition: |
Potassium |
9.95 % |
K |
11.98 % |
K2O |
|
Sodium |
1.75 % |
Na |
2.36 % |
Na2O |
|
Lithium |
3.00 % |
Li |
6.46 % |
Li2O |
|
Aluminum |
6.86 % |
Al |
12.97 % |
Al2O3 |
|
Silicon |
28.58 % |
S |
61.14 % |
SiO2 |
|
Hydrogen |
0.26 % |
H |
2.29 % |
H2O |
|
Oxygen |
44.77 % |
O |
|
|
|
Fluorine |
4.83 % |
F |
4.83 % |
F |
|
— |
—
% |
F |
-2.03 % |
-O=F2 |
|
|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
|
|
Classification
|
|
|
Mineral
Classification: |
Silicates
|
Strunz 8th
Ed. ID:
|
8/H.11-10
|
Nickel-Strunz 10th
Ed. ID:
|
9.EC.20
|
|
9 : SILICATES (Germanates)
E : Phyllosilicates C : Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
|
Related
to: |
Mica Group.
Polylithionite-Trilithionite Series.
|
Members
of Group: |
Mica
Group: Aluminoceldonite, Anandite, Annite, Annite-Phlogopite
Series, Aspidolite, Balestraite, Biotite, Bityite, Boromuscovite,
Brammallite, Celadonite, Chernykhite, Chromceladonite,
Chromphyllite, Clintonite, Eastonite, Ephesite, Ferroaluminoceladonite,
Ferroceladonite, Ferrokinoshitalite, Fluorannite, Fluorphlogopite,
Ganterite, Glauconite, Hendricksite, Illite, Kinoshitalite,
Lepidolite, Luanshiweiite, Margarite, Masutomilite,
Montdorite, Muscovite, Muscovite-Celadonite Series,
Nanpingite, Natro-glauconite, Norrishite, Oxykinoshitalite,
Oxyphlogopite, Paragonite, Phengite, Phlogopite, Polylithionite,
Preiswerkite, Roscoelite, Shirokshinite, Shirozulite,
Siderophyllite, Sokolovaite, Suhailite, Tainiolite,
Tetraferriannite, Tetraferriphlogopite, Tobelite, Trilithionite,
Voloshinite, Wonesite, Yangzhumingite, Zinnwaldite
|
Varieties: |
Cs-bearing Polylithionite
|
Synonyms: |
ICSD 34336 (with F),
PDF 21952
|
|
|
Crystal
Data
|
|
|
Crystallography:
|
Monoclinic - Prismatic
|
Crystal
Habit:
|
Pseudohexagonal
crystals, tabular || f001g, to 10 cm. As irregularly
shaped aggregates of fine scaly crystals.
|
Twinning:
|
None
|
|
|
Physical
Properties
|
|
|
Cleavage: |
Perfect
on {001}
|
Fracture: |
Irregular/Uneven
|
Tenacity:
|
Brittle
|
Moh's
Hardness: |
2.0
- 3.0
|
Density:
|
2.58
- 2.82 (g/cm3)
|
Luminescence:
|
May
fluoresce lemon-yellow under SW UV |
Radioactivity:
|
Barely
Detectable;
GRapi = 141.95 (Gamma Ray American Petroleum Institute Units)
|
|
|
Optical
Properties
|
|
|
Color: |
Bright
to pale pink, cream to white, colorless, pale brown
to yellow-brown, bluish, greenish; in transmitted light,
colorless
|
Transparency: |
Transparent
|
Luster: |
Pearly
to waxy when fine-grained |
Refractive
Index: |
1.530
- 1.559 Biaxial ( - )
|
Birefringence: |
0.025
- 0.029
|
Dispersion: |
Weak |
Pleochroism: |
n/a |
|
|
Occurances
|
|
|
Geological
Setting: |
In
irregular segregations and veinlets, as a late-stage
and metasomatic replacement mineral, in syenite pegmatites
in a differentiated alkalic massif (Lovozero massif,
Russia). |
Common
Associations: |
Microcline,
Natrolite, Taeniolite, Steenstrupine, Aegirine, Analcime,
Epistolite
|
Common
Impurities: |
Ti,
Fe, Mn, Mg, Ca, Na, H2O
|
Type
Locality: |
Kangerluarsuk Fjord (Kangerdluarssuq Fjord), Ilímaussaq complex, Narsaq, Kujalleq, Greenland
|
Year
Discovered: |
1884
|
View
mineral photos: |
Polylithionite
Mineral Photos and Locations |
|
|
More
Information
|
|
|
|
Mindat.org
Webmineral.com
|
|
|
Polylithionite
is named from the Greek word
poly meaning many or much, in allusion to its composition with a high LITHIum content. Polylithionite
is a member of the Mica Group of minerals that also
includes Celadonite,
Lepidolite,
Muscovite
and Phlogopite.
Polylithionite
can often be found as attractive rosette crystal
clusters resembling the petals of a flower and often
associated ith Sérandite.
Polylithionite is rarely available as a gemstone
but a recent find in Pakistan has produced gemmy Pollucite crystals
containing tiny crystal inclusions of Polylithionite.
Magnification must be used to observe these tiny
Polylithionite crystals which have good crystal
forms. Polylithionite may fluoresce lemon yellow to
pale yellowish white under shortwave UV light.
Locations
for Polylithionite: On the Kangerdluarssuk Plateau
and elsewhere in the Ilímaussaq intrusion, southern
Greenland. In Russia, found on Mts. Karnasurt and Lepkhe-Nelm,
Lovozero massif, Kola Peninsula. In the Dara-i-Pioz
massif, Alai Range, Tien Shan, Tajikistan. At Vøra,
Sandefjord, Oslo region, Norway. From Mont Saint-Hilaire
and near Saint-Amable, Quebec, Canada. In the USA, at
Point of Rocks, Colfax County, New Mexico. On Mt. Malosa,
Zomba district, Malawi.
|
Polylithionite
gems for sale:
We
have not photographed our Polylithionite gems yet. Please
check back soon.
|
|