Tunellite Mineral Data
General Tunellite Information
Chemical Formula:
SrB6O9(OH)2•3(H2O)
Composition:
Molecular Weight = 384.54 gm
Strontium 22.79 % Sr 26.95 % SrO
Boron 16.87 % B 54.31 % B2 O3
Hydrogen 2.10 % H 18.74 % H2 O
Oxygen 58.25 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
SrB6 O9 (OH)2 •3(H2 O)
Environment:
Borate deposits.
IMA Status:
Approved IMA 1961
Locality:
U. S. Borax open pit, Boron, Kern Co., California. Link to MinDat.org Location Data.
Name Origin:
Named for George Tunnel (1900-1996), U. S. Mineralogist.
Name Pronunciation:
Tunellite + Pronunciation
Synonym:
Balavinskite ?
ICSD 15479
PDF 14-616
Tunellite Image
Images:
Tunellite Crystallography
Axial Ratios:
a:b:c =1.7521:1:1.2095
Cell Dimensions:
a = 14.39, b = 8.213, c = 9.934, Z = 4; beta = 114.067° V = 1,071.99 Den(Calc)= 2.38
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /a
X Ray Diffraction:
By Intensity(I/Io ): 6.57(1), 5.135(0.3), 6.97(0.25),
Physical Properties of Tunellite
Cleavage:
{100} Perfect, {001} Distinct
Color:
Colorless.
Density:
2.4
Diaphaneity:
Transparent
Habit:
Nodular - Tuberose forms having irregular protuberances over the surface.
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Habit:
Tabular - Form dimensions are thin in one direction.
Hardness:
2.5 - Finger Nail
Luminescence:
Fluorescent, Short UV=butter yellow, Long UV=butter yellow.
Luster:
Vitreous - Pearly
Streak:
white
Optical Properties of Tunellite
Gladstone-Dale:
CI meas = -0.026 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = -0.035 (Excellent) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2272,KPDmeas = 0.2253,KC = 0.2196 Ncalc = 1.52 - 1.53
Optical Data:
Biaxial (+), a=1.519, b=1.534, g=1.569, bire=0.0500
Pleochroism (x):
colorless.
Pleochroism (y):
colorless.
Pleochroism (z):
colorless.
Calculated Properties of Tunellite
Electron Density:
Bulk Density (Electron Density)=2.35 gm/cc note: Specific Gravity of Tunellite =2.40 gm/cc.
Fermion Index:
Fermion Index = 0.04 Boson Index = 0.96
Photoelectric:
PETunellite = 24.87 barns/electronU=PETunellite x r Electron Density= 58.36 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Tunellite is Not Radioactive
Tunellite Classification
Dana Class:
26.06.06.02 (26) Hydrated Borates Containing Hydroxyl or Halogen
(26.06) Dana Type
(26.06.06) Dana Group
26.06.06.01 Nobleite CaB6O9(OH)2•3(H2O) P 21 /a 2/m
26.06.06.02 Tunellite SrB6O9(OH)2•3(H2O) P 21 /a 2/m
Strunz Class:
06.FC.05 06 - BORATES
06.F - Hexaborates
06.FC -Phyllo-hexaborates
06.FC.05 Balavinskite ? Sr2B6O11•4(H2O) Mono ? Mono
06.FC.05 Nobleite CaB6O9(OH)2•3(H2O) P 21 /a 2/m
06.FC.05 Tunellite SrB6O9(OH)2•3(H2O) P 21 /a 2/m
Other Tunellite Information
References:
NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Tunellite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST
Search for Tunellite using:
[AOL ]
[Bing ]
[Dog Pile ]
[GeoScienceWorld ]
[HotBot ]
[Ixquick ]
[Lycos ]
[MAMMA ]
[Scirus ]
[Teoma ]
[WebCrawler ]
[Wikipedia ]
[YAHOO ]
Visit our Advertisers for Tunellite :
Ask about Tunellite 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
Espaņol
Print or Cut-and-Paste your Tunellite Specimen Label here :
Tunellite
SrB6O9(OH)2•3(H2O)
Dana No: 26.06.06.02 Strunz No: 06.FC.05
Locality:
Notes:
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.