Gearksutite Mineral Data

Gearksutite Mineral Data +

[Fine Minerals] [What's New] [Mineral Galleries] [My Collection] [Mineral Auctions]
Dan Weinrich Fine Minerals
Full-time professional mineral dealer with over 31 years experience in mineral collecting
And 15 years selling mineral specimens on the internet and at major mineral shows

General Gearksutite Information

Chemical Formula:

CaAl(OH,F)5·(H2O)

Composition:

Molecular Weight = 178.08 gm

Calcium 22.51 % Ca 31.49 % CaO

Aluminum 15.15 % Al 28.63 % Al₂O₃

Hydrogen 1.70 % H 15.17 % H₂O

Oxygen 17.97 % O

Fluorine 42.67 % F 42.67 % F

- % F -17.97 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CaAl(OH)F₄·(H₂O)

Environment:

Alteration product of cryolite.

IMA Status:

Valid Species (Pre-IMA) 1868

Locality:

Greenland and Ural Mountains, Russia. Link to MinDat.org Location Data.

Name Origin:

Named from the Greek "Ge", for earth because it is usually earthy and arksutite, from the locality near Arksut fjord.

Synonym:

ICSD 89800

Gearksutite Image

Images:

Gearksutite

Comments: White gearksutite crust on quartz.
Location: Saint Peter's Dome, El Paso County, Colorado, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Gearksutite Crystallography

Crystal System:

Monoclinic

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

By Intensity(I/I_o): 4.55(1), 2.28(0.8), 3.15(0.8),

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

Marchetti F , Perchiazzi N , American Mineralogist , 85 (2000) p.231-235, The crystal structure of gearksutite, CaAlF4(OH).H2O

Physical Properties of Gearksutite

Cleavage:

None

Color:

White.

Density:

2.75

Diaphaniety:

Transparent to subtranslucent

Fracture:

Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).

Hardness:

2 - Gypsum

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Dull

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Gearksutite

Gladstone-Dale:

CI meas= 0.165 (Poor) - where the CI = (1-KPDmeas/KC)
KPDmeas= 0.1646,KC= 0.197

Optical Data:

Biaxial (-), a=1.448, b=1.454, g=1.456, bire=0.0080

Calculated Properties of Gearksutite

Electron Density:

r_electron=2.72 gm/cc
note: r_Gearksutite=2.75 gm/cc.

Fermion Index

Fermion Index = 0.00039
Boson Index = 0.99961

Photoelectric:

PE_Gearksutite= 3.48 barns/electron
U=PE_Gearksutite x r_electron= 9.46 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Gearksutite is Not Radioactive

Gearksutite Classification

Dana Class:

11.6.8.1 (11)Halide Complexes; Alumino-fluorides

(11.6)with miscellaneous formulae

(11.6.8)Dana Group

11.6.8.1 Gearksutite CaAl(OH,F)5·(H2O) Mono

Strunz Class:

III/C.01-10 III - Halogenides

III/C - Double halogenides with water, Fluorides

III/C.01 - Gearksutite - Chukhrovite - (Ce) series

III/C.01-10 Gearksutite CaAl(OH,F)5·(H2O) Mono

III/C.01-20 Acuminite SrAlF4(OH)·(H2O) C 2/c 2/m

III/C.01-30 Tikhonenkovite SrAl(OH)F4·(H2O) Unk Mono

III/C.01-35 Artroeite PbAlF3(OH)2 P1 1

III/C.01-40 Creedite Ca3Al2(SO4)(F,OH)10·2(H2O) C 2/c 2/m

III/C.01-50 Chukhrovite-(Y) Ca3(Y,Ce)Al2(SO4)F13·10(H2O) F d3 2/m 3

III/C.01-60 Chukhrovite-(Ce) Ca3(Ce,Y)Al2(SO4)F13·10(H2O) F d3 2/m 3

Other Gearksutite Information

References:

NAME( Dana8) PHYS. PROP.(Dana) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

Search for Gearksutite using:

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

Visit our Advertisers for Gearksutite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Gearksutite Mineral Data :

Ask about Gearksutite 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 Gearksutite Specimen Label here :

Gearksutite

CaAl(OH,F)5·(H2O)
Dana No: 11.6.8.1 Strunz No: III/C.01-10
Locality:

Notes: