Petalite Mineral Data

Petalite Mineral Data +

[Mineral Forums] [Minerals for Sale] [About Us] [En Espanol] [Mineral Gallery]
Fabre Minerals - Europe's first Internet mineral dealer, on the web since 1996

General Petalite Information

Chemical Formula:

LiAlSi4O10

Composition:

Molecular Weight = 305.15 gm

Lithium 2.09 % Li 4.50 % Li₂O

Aluminum 8.75 % Al 16.54 % Al₂O₃

Silicon 36.72 % Si 78.56 % SiO₂

Oxygen 52.43 % O

______ ______

100.00 % 99.61 % = TOTAL OXIDE

Empirical Formula:

Li_0.92Al_0.99Si_3.99O₁₀

Environment:

In granite pegmatites, locally constituting an ore of lithium.

IMA Status:

Valid Species (Pre-IMA) 1800

Locality:

Mining Academy, Freiberg, Germany, Link to MinDat.org Location Data.

Name Origin:

From the Greek petalon - "leaf" in allusion to the perfect basal cleavage.

Synonym:

ICSD 100348

PDF 35-463

Petalite Image

Images:

Petalite

Comments: Translucent, gemmy , equant petalite crystal with an etched surface texture resulting in irregular faces.
Location: Paprok, Konar (Kunar; Konarh; Konarha; Nuristan) Province, Afghanistan. Scale: 5x3.5x3 cm.
© John Betts - Fine Minerals

Petalite Crystallography

Axial Ratios:

a:b:c =2.2869:1:1.4845

Cell Dimensions:

a = 11.754, b = 5.1395, c = 7.6296, Z = 2; beta = 113.04° V = 424.14 Den(Calc)= 2.39

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2/a

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.7255(1), 3.7341(0.95), 3.6734(0.75),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Tagai T , Ried H , Joswig W , Korekawa M , Zeitschrift fur Kristallographie , 160 (1982) p.159-170, Kristallographische untersuchungen eines petalits mittels neutronenbeugung und, transmissionselektronenmikroskopie, Locality: Varutrask, Sweden

Physical Properties of Petalite

Cleavage:

[001] Perfect, [???] Imperfect

Color:

Colorless, Gray, Yellow, Yellow gray, White.

Density:

2.39 - 2.46, Average = 2.42

Diaphaniety:

Transparent to translucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

6-6.5 - Orthoclase-Pyrite

Luminescence:

Fluorescent.

Luster:

Vitreous - Pearly

Streak:

colorless

Optical Properties of Petalite

Gladstone-Dale:

CI meas= 0.006 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2134,KPDmeas= 0.2103,KC= 0.2115

Optical Data:

Biaxial (+), a=1.504, b=1.51, g=1.516, bire=0.0120

Calculated Properties of Petalite

Electron Density:

r_electron=2.41 gm/cc
note: r_Petalite=2.43 gm/cc.

Fermion Index

Fermion Index = 0.01897
Boson Index = 0.98103

Photoelectric:

PE_Petalite= 1.69 barns/electron
U=PE_Petalite x r_electron= 4.06 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Petalite is Not Radioactive

Petalite Classification

Dana Class:

72.6.1.1 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings

(72.6)with tetrahedral Al cross-linking

(72.6.1)Dana Group

72.6.1.1 Petalite LiAlSi4O10 P 2/a 2/m

Strunz Class:

VIII/J.03-10 VIII - Silicates

VIII/J - Tectosilicates (network) without anions unfamiliar to the tetraheders

VIII/J.03 - Petalite - Virgilite series

VIII/J.03-10 Petalite LiAlSi4O10 P 2/a 2/m

VIII/J.03-20 Virgilite LixAlxSi3-xO6 P 6₂22,P 6₄22 6 2 2

VIII/J.03-30 Lisitsynite! KBSi2O6 P 2₁2₁2₁ 2 2 2

Other Petalite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Petalite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - MinMax(Deutsch)
11 - MinMax(English)
12 - Mineralienatlas (Deutsch)
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - Scandinavian mineral gallery
16 - Tradeshop.com - The Rainbow of Gems
17 - WWW-MINCRYST

Search for Petalite using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Petalite :

AA Mineral Specimens

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

MineralsWeb Fine Minerals

The GeoZone

Wrights Rock Shop

Translate Petalite Mineral Data :

Ask about Petalite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Petalite Specimen Label here :

Petalite

LiAlSi4O10
Dana No: 72.6.1.1 Strunz No: VIII/J.03-10
Locality:

Notes: