Tunellite Mineral Data

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 % B₂O₃

Hydrogen 2.10 % H 18.74 % H₂O

Oxygen 58.25 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

SrB₆O₉(OH)₂·3(H₂O)

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.

Synonym:

Balavinskite ?

ICSD 15479

PDF 14-616

Tunellite Image

Images:

Tunellite

Comments: Clear, prismatic crystals of tunellite on matrix.
Location: Death Valley, Inyo County, California, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

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

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

By Intensity(I/I_o): 6.57(1), 5.135(0.3), 6.97(0.25),

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

Clark J R , American Mineralogist , 49 (1964) p.1549-1568, The crystal structure of tunellite, SrB6O9(OH)2.3H2O

View Additional jPOWD Structure files for Tunellite
[1]

Physical Properties of Tunellite

Cleavage:

[100] Perfect, [001] Distinct

Color:

Colorless.

Density:

2.4

Diaphaniety:

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.

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

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:

r_electron=2.35 gm/cc
note: r_Tunellite=2.40 gm/cc.

Fermion Index

Fermion Index = 0.04979
Boson Index = 0.95021

Photoelectric:

PE_Tunellite= 24.87 barns/electron
U=PE_Tunellite x r_electron= 58.36 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Tunellite is Not Radioactive

Tunellite Classification

Dana Class:

26.6.6.2 (26)Hydrated Borates Containing Hydroxyl or Halogen

(26.6)Dana Type

(26.6.6)Dana Group

26.6.6.1 Nobleite CaB6O9(OH)2·3(H2O) P 2₁/a 2/m

26.6.6.2 Tunellite SrB6O9(OH)2·3(H2O) P 2₁/a 2/m

Strunz Class:

V/K.06-20 V - Nitrates, Carbonates and Borates

V/K - Layered borates with complex groups [Bx(O,OH)y]

V/K.06 - Nobleite - Balavinskite series

V/K.06-10 Nobleite CaB6O9(OH)2·3(H2O) P 2₁/a 2/m

V/K.06-20 Tunellite SrB6O9(OH)2·3(H2O) P 2₁/a 2/m

V/K.06-30 Balavinskite? Sr2B6O11·4(H2O) Mono ? Mono

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 -Google Images 5 -Google Scholar 6 -Handbook of Mineralogy (UofA) 7 -MinDAT 8 -MinMax(Deutsch) 9 -MinMax(English) 10 -Mineralienatlas (Deutsch) 11 -QUT Mineral Atlas 12 - WWW-MINCRYST 13 -École des Mines de Paris

Search for Tunellite using:

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

Visit our Advertisers for Tunellite :
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 Tunellite Mineral Data :

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 Español

Print or Cut-and-Paste your Tunellite Specimen Label here :

Tunellite

SrB6O9(OH)2·3(H2O)
Dana No: 26.6.6.2 Strunz No: V/K.06-20
Locality:

Notes: