Colemanite Mineral Data

Colemanite Mineral Data +

General Colemanite Information

Chemical Formula:

Ca2B6O11·5(H2O)

Composition:

Molecular Weight = 411.09 gm

Calcium 19.50 % Ca 27.28 % CaO

Boron 15.78 % B 50.81 % B₂O₃

Hydrogen 2.45 % H 21.91 % H₂O

Oxygen 62.27 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂B₆O₁₁·5(H₂O)

Environment:

Lacusterine limestone hosted borate deposits.

IMA Status:

Valid Species (Pre-IMA) 1884

Locality:

Furnace Creek district, Death Valley, Inyo Co. California. Link to MinDat.org Location Data.

Name Origin:

After William T. Coleman, owner of the Death Valley, California mine where this species was first found.

Synonym:

ICSD 75921

Neocolmanite

PDF 33-267

Colemanite Image

Images:

Colemanite

Comments: Coarsely crystalline colemanite, in part, covered with minute acicular crystals of strontianite.
Location: Boraxo #3 pit, Death Valley, California, USA. Scale: 30 cm.
© Dave Barthelmy

Images:

Colemanite

Comments: Large crystals of brown colemanite with second generation of absolutely clear and gemmy (colorless) colemanite. Intensely fluorescent in long and short UV..
Location: Mustafakemalpascha Mine, West-Anatolia Turkey. Scale: Crystal size: 1.3 x 1 cm.
© Fabre Minerals

Colemanite Crystallography

Axial Ratios:

a:b:c =0.7761:1:0.5417

Cell Dimensions:

a = 8.743, b = 11.264, c = 6.102, Z = 2; beta = 110.116° V = 564.27 Den(Calc)= 2.42

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/a

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

By Intensity(I/I_o): 3.13(1), 3.85(0.5), 5.64(0.5),

Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: [ 1 2 1] [ 1 1 1] [ 1 0 0] [ 1 1 1] [ 1 1 0] [ 0 0 1]

Warning: this large pop-up is very compute intensive and may not work well with some computers.

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

Burns P C , Hawthorne F C , The Canadian Mineralogist , 31 (1993) p.297-304, Hydrogen bonding in colemanite: An X-ray and structure-energy study

Physical Properties of Colemanite

Cleavage:

[010] Perfect, [001] Distinct

Color:

Colorless, Gray, Gray white, Yellowish white, White.

Density:

2.42

Diaphaniety:

Transparent to translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Blocky - Crystal shape tends to be equant (e.g. feldspars).

Habit:

Crystalline - Coarse - Occurs as well-formed coarse sized crystals.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

4.5 - Between Fluorite and Apatite

Luminescence:

None.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Colemanite

Gladstone-Dale:

CI meas= -0.024 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2468,KPDmeas= 0.2468,KC= 0.241

Optical Data:

Biaxial (+), a=1.586, b=1.592, g=1.614, bire=0.0280, 2V(Calc)=56, 2V(Meas)=55-56. Dispersion relatively weak.

Calculated Properties of Colemanite

Electron Density:

r_electron=2.45 gm/cc
note: r_Colemanite=2.42 gm/cc.

Fermion Index

Fermion Index = 0.03196
Boson Index = 0.96804

Photoelectric:

PE_Colemanite= 2.61 barns/electron
U=PE_Colemanite x r_electron= 6.38 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Colemanite is Not Radioactive

Colemanite Classification

Dana Class:

26.3.5.1 (26)Hydrated Borates Containing Hydroxyl or Halogen

(26.3)Dana Type

(26.3.5)Dana Group

26.3.5.1 Colemanite Ca2B6O11·5(H2O) P 2₁/a 2/m

Strunz Class:

V/J.03-10 V - Nitrates, Carbonates and Borates

V/J - Chain borates with [B2O4]2- to [B6O10]2-

V/J.03 - Colemanite - Hydroboracite series

V/J.03-10 Colemanite Ca2B6O11·5(H2O) P 2₁/a 2/m

V/J.03-20 Hydroboracite CaMgB6O8(OH)6·3(H2O) P 2/c 2/m

Other Colemanite Information

References:

NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Sinkankas66)

Search for Colemanite using:

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

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

Translate Colemanite Mineral Data :

Ask about Colemanite 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 Colemanite Specimen Label here :

Colemanite

Ca2B6O11·5(H2O)
Dana No: 26.3.5.1 Strunz No: V/J.03-10
Locality:

Notes: