Borocookeite Mineral Data

General Borocookeite Information

Chemical Formula:

Li(1+3x)Al(4-x)(BSi3)O10(OH,F)8 [x = 0-0.33]

Composition:

Molecular Weight = 502.73 gm

Lithium 2.21 % Li 4.76 % Li₂O

Aluminum 20.39 % Al 38.53 % Al₂O₃

Silicon 16.76 % Si 35.85 % SiO₂

Boron 1.29 % B 4.15 % B₂O₃

Hydrogen 1.56 % H 13.98 % H₂O

Oxygen 56.65 % O

Fluorine 1.13 % F 1.13 % F

- % F -0.48 % -O=F₂

______ ______

100.00 % 97.93 % = TOTAL OXIDE

Empirical Formula:

Li_1.6Al_3.8B_0.6Si₃O₁₀F_0.3(OH)_7.8

Environment:

Late stage pocket species in tourmaline-rich miarolitic pegmatites.

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Malkhan gem tourmaline deposit, Central Transbaikalia, Russia. Link to MinDat.org Location Data.

Name Origin:

Named as the boron-rich analog of cookeite.

Synonym:

IMA2000-013

Borocookeite Image

Images:

Borocookeite

Comments: Black and white image of multicolored tourmaline crystals (1) in fine-flaky aggregate of borocookeite (2). (AmMin, v 88, p 831).
Location: Sosedka and Mokhovaya pegmatite veins, Malkhan gem tourmaline deposit, Chikoy district, Chita oblast, Russia. Scale: Sample size is 5 x 5 cm.
© American Mineralogist

Borocookeite Crystallography

Axial Ratios:

a:b:c =0.5782:1:1.589

Cell Dimensions:

a = 5.121, b = 8.856, c = 14.073, Z = 2; beta = 96.93° V = 633.57 Den(Calc)= 2.64

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: pseudo C 2/m

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

By Intensity(I/I_o): 3.512(1)(004), 14.1(1)(001), 4.71(0.7)(003),7.05(0.5)(002), 2.807(0.2)(005), 1.946(0.17)(204), 2.304(0.16)(202), 2.332(0.14)(006), 1.62(0.1)(206),

Physical Properties of Borocookeite

Cleavage:

{001} Perfect

Color:

Light pinkish gray.

Density:

2.62

Diaphaneity:

Opaque to translucent

Fracture:

Flexible - Flexible fragments.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Flakes - Flat, thin crystals or aggregates.

Hardness:

3 - Calcite

Luster:

Greasy (Oily)

Streak:

white

Optical Properties of Borocookeite

Gladstone-Dale:

CI meas= 0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.025 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2203,KPDmeas= 0.222,KC= 0.2259
Ncalc = 1.59 - 1.6

Optical Data:

Biaxial (?), a=1.574, b=1.58, g=1.591, bire=0.0170

Calculated Properties of Borocookeite

Electron Density:

Bulk Density (Electron Density)=2.63 gm/cc
note: Specific Gravity of Borocookeite =2.62 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Borocookeite= 1.32 barns/electron
U=PE_Borocookeite x rElectron Density= 3.46 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Borocookeite is Not Radioactive

Borocookeite Classification

Dana Class:

71.04.01.10 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.04)interlayered 1:1, 2:1, and octahedra

(71.04.01)Chlorite group (Tri-Dioctahedral)

71.04.01.01 Donbassite Al2[Al2.33][Si3AlO10](OH)8 C 2/m 2/m

71.04.01.02 Cookeite LiAl4(Si3Al)O10(OH)8 P 2₁/a 2/m

71.04.01.03 Sudoite Mg2(Al,Fe)3Si3AlO10(OH)8 C 2/m 2/m

71.04.01.04 Clinochlore (Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

71.04.01.05 Nimite (Ni,Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

71.04.01.06 Baileychlore (Zn,Al,[])3[Fe2Al][Si3AlO10](OH)8 C1,C1 Tri

71.04.01.07 Chamosite (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C 2/m 2/m

71.04.01.08 Pennantite Mn5Al(Si3Al)O10(OH)8 C 2/m 2/m

71.04.01.09 Orthochamosite! (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C3m-pseudoHEX Ortho

71.04.01.10 Borocookeite! Li(13x)Al(4-x)(BSi3)O10(OH,F)8[x=0-0.33] pseudo C 2/m 2/m

Strunz Class:

09.EC.55 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.55 Donbassite Al2[Al2.33][Si3AlO10](OH)8 C 2/m 2/m

09.EC.55 Baileychlore (Zn,Al,[])3[Fe2Al][Si3AlO10](OH)8 C1,C1 Tri

09.EC.55 Clinochlore (Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

09.EC.55 Cookeite LiAl4(Si3Al)O10(OH)8 P 2₁/a 2/m

09.EC.55 Chamosite (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C 2/m 2/m

09.EC.55 Franklinfurnaceite Ca2(Fe,Al)MnMn3Zn2Si2O10(OH)8 C 2 2

09.EC.55 Nimite (Ni,Mg,Fe)5Al(Si3Al)O10(OH)8 C 2/m 2/m

09.EC.55 Gonyerite Mn3[Mn3Fe][(Si,Fe)4O10](OH,O)8 pseudo-HEX Ortho

09.EC.55 Odinite (Fe,Mg,Al,Fe,Ti,Mn)2.5(Si,Al)2O5(OH)4 Cm m

09.EC.55 Orthochamosite (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 C3m-pseudoHEX Ortho

09.EC.55 Pennantite Mn5Al(Si3Al)O10(OH)8 C 2/m 2/m

09.EC.55 Sudoite Mg2(Al,Fe)3Si3AlO10(OH)8 C 2/m 2/m

09.EC.55 Glagolevite! NaMg6[Si3AlO10](OH,O)8•H2O C1 1

09.EC.55 Borocookeite! Li(13x)Al(4-x)(BSi3)O10(OH,F)8[x=0-0.33] pseudo C 2/m 2/m

Other Borocookeite Information

References:

NAME( AmMin, v 88, p 830) PHYS. PROP.(AmMin, v 88, p 830) OPTIC PROP.(AmMin, v 88, p 830)

See Also:

Links to other databases for Borocookeite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Borocookeite

Li(1+3x)Al(4-x)(BSi3)O10(OH,F)8 [x = 0-0.33]
Dana No: 71.04.01.10 Strunz No: 09.EC.55
Locality:

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