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 % B2 O3
Hydrogen 2.45 % H 21.91 % H2 O
Oxygen 62.27 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Ca2 B6 O11 •5(H2 O)
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.
Name Pronunciation:
Colemanite + Pronunciation
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 - Prismatic H-M Symbol (2/m) Space Group: P 21 /a
X Ray Diffraction:
By Intensity(I/Io ): 3.13(1), 3.85(0.5), 5.64(0.5),
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Physical Properties of Colemanite
Cleavage:
{010} Perfect, {001} Distinct
Color:
Colorless, Gray, Gray white, Yellowish white, White.
Density:
2.42
Diaphaneity:
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:
Fluorescent, Short UV=yellow, blue white, Long UV=yellow, blue white.
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 Ncalc = 1.58
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:
Bulk Density (Electron Density)=2.45 gm/cc note: Specific Gravity of Colemanite =2.42 gm/cc.
Fermion Index:
Fermion Index = 0.03 Boson Index = 0.97
Photoelectric:
PEColemanite = 2.61 barns/electronU=PEColemanite x r Electron Density= 6.38 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Colemanite is Not Radioactive
Colemanite Classification
Dana Class:
26.03.05.01 (26) Hydrated Borates Containing Hydroxyl or Halogen
(26.03) Dana Type
(26.03.05) Dana Group
26.03.05.01 Colemanite Ca2B6O11•5(H2O) P 21 /a 2/m
Strunz Class:
06.CB.10 06 - BORATES
06.C - Triborates
06.CB -Ino-triborates
06.CB.10 Colemanite Ca2B6O11•5(H2O) P 21 /a 2/m
Other Colemanite Information
References:
NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Sinkankas66)
See Also:
Links to other databases for Colemanite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Glendale Community College
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineral and Gemstone Kingdom
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - Philatelic Mineralogy
17 - QUT Mineral Atlas
18 - Ruff.Info
19 - WWW-MINCRYST
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Colemanite
Ca2B6O11•5(H2O)
Dana No: 26.03.05.01 Strunz No: 06.CB.10
Locality:
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