Dickite Mineral Data

Dickite Mineral Data +

General Dickite Information

Chemical Formula:

Al2Si2O5(OH)4

Composition:

Molecular Weight = 258.16 gm

Aluminum 20.90 % Al 39.50 % Al₂O₃

Silicon 21.76 % Si 46.55 % SiO₂

Hydrogen 1.56 % H 13.96 % H₂O

Oxygen 55.78 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al₂Si₂O₅(OH)₄

IMA Status:

Valid Species (Pre-IMA) 1930

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named after the Scottish chemist, A. B. Dick.

Dickite Image

Images:

Dickite Ankerite Sphalerite

Comments: White, rhombohedral crystals of ankerite and dark gray, metallic sphalerite on beige dickite.
Location: Prego mine, Kladno, Czech Rebublic. Scale: Picture size 2 cm.
© Dave Barthelmy

Images:

Dickite

Comments: Porcelaneous pure white massive dickite.
Location: Beaver County, Utah, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Dickite Crystallography

Axial Ratios:

a:b:c =0.576:1:1.6135

Cell Dimensions:

a = 5.1375, b = 8.9178, c = 14.389, Z = 4; beta = 96.74° V = 654.68 Den(Calc)= 2.62

Crystal System:

Monoclinic - DomaticH-M Symbol (m) Space Group: Cc

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

By Intensity(I/I_o): 3.58(1), 7.15(1), 2.33(0.9),

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

Bailey S W , American Mineralogist , 48 (1963) p.1196-1209, Polymorphism of the kaolin minerals

View Additional jPOWD Structure files for Dickite
[1] [2]

Physical Properties of Dickite

Cleavage:

[001] Perfect

Color:

Blue, Colorless, Gray, Yellow brown, White.

Density:

2.6

Diaphaniety:

Subtranslucent to opaque

Fracture:

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

Habit:

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

Hardness:

1.5-2 - Talc-Gypsum

Luster:

Pearly

Streak:

white

Optical Properties of Dickite

Gladstone-Dale:

CI meas= 0.042 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.049 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2149,KPDmeas= 0.2166,KC= 0.226

Optical Data:

Biaxial (+), a=1.558-1.562, b=1.56-1.565, g=1.563-1.571, bire=0.0050-0.0090, 2V(Calc)=72-80, 2V(Meas)=52-80. Dispersion none.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Dickite

Electron Density:

r_electron=2.62 gm/cc
note: r_Dickite=2.60 gm/cc.

Fermion Index

Fermion Index = 0.01043
Boson Index = 0.98957

Photoelectric:

PE_Dickite= 1.48 barns/electron
U=PE_Dickite x r_electron= 3.87 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Dickite is Not Radioactive

Dickite Classification

Dana Class:

71.1.1.1 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.1)with 1:1 layers

(71.1.1)Kaolinite group

71.1.1.1 Dickite Al2Si2O5(OH)4 Cc m

71.1.1.2 Kaolinite Al2Si2O5(OH)4 P1 1

71.1.1.3 Nacrite Al2Si2O5(OH)4 Cc m

71.1.1.4 Halloysite Al2Si2O5(OH)4 Cc m

71.1.1.4a Endellite? Al2Si2O5(OH)4·2(H2O) Cc m

71.1.1.5 Odinite (Fe,Mg,Al,Fe,Ti,Mn)2.5(Si,Al)2O5(OH)4 Cm m

Strunz Class:

VIII/H.25-20 VIII - Silicates

VIII/H - Phyllosilicates (layered) Mica like with [Si4O10]4- and related groups

VIII/H.25 - Kaolinite group

VIII/H.25-10 Kaolinite Al2Si2O5(OH)4 P1 1

VIII/H.25-20 Dickite Al2Si2O5(OH)4 Cc m

VIII/H.25-30 Nacrite Al2Si2O5(OH)4 Cc m

VIII/H.25-40 Halloysite Al2Si2O5(OH)4 Cc m

Other Dickite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

Search for Dickite using:

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

Visit our Advertisers for Dickite :
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 Dickite Mineral Data :

Ask about Dickite 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 Dickite Specimen Label here :

Dickite

Al2Si2O5(OH)4
Dana No: 71.1.1.1 Strunz No: VIII/H.25-20
Locality:

Notes: