Tuscanite Mineral Data

Tuscanite Mineral Data +

We specialise in top quality, fine minerals from Morocco, Namibia,
South Africa, Pakistan, Democratic Republic of Congo (ZaÃƒï¿½Ã‚Â¯re) and China
Worldwide Fine Minerals by B & C GOBIN

General Tuscanite Information

Chemical Formula:

K(Ca,Na)6(Si,Al)10O22(SO4,CO3,(OH)2)·(H2O)

Composition:

Molecular Weight = 1,101.39 gm

Potassium 3.19 % K 3.85 % K₂O

Sodium 1.04 % Na 1.41 % Na₂O

Calcium 19.29 % Ca 26.99 % CaO

Magnesium 0.22 % Mg 0.37 % MgO

Aluminum 9.06 % Al 17.13 % Al₂O₃

Iron 0.51 % Fe 0.65 % FeO

Silicon 16.07 % Si 34.37 % SiO₂

Hydrogen 0.27 % H 2.45 % H₂O

Carbon 0.65 % C 2.40 % CO₂

Sulfur 4.08 % S 10.18 % SO₃

Oxygen 45.61 % O

______ ______

100.00 % 99.78 % = TOTAL OXIDE

Empirical Formula:

K_0.9Ca_5.3Na_0.5Mg_0.1Fe²⁺_0.1Si_6.3Al_3.7O₂₂(SO₄)_1.4(CO₃)_0.6(OH)·(H₂O)

Environment:

Within ejected blocks of metasomatized carbonate rocks in a pumice deposit.

IMA Status:

Approved IMA 1977

Locality:

Latera caldera, Pitigliano, near Grosseto, Tuscan, and at Sacrofano, Lazio, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for the Tuscany region of Italy where the mineral was first found.

Synonym:

ICSD 9683

PDF 29-1035

Tuscanite Image

Images:

Tuscanite Augite

Comments: Translucent tuscanite microcrystal in in vug in low-Fe augite (var. fassaite).
Location: Pitigliano Quarry, Grosseto, Tuscany, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Tuscanite Crystallography

Axial Ratios:

a:b:c =4.7037:1:2.1307

Cell Dimensions:

a = 24.036, b = 5.11, c = 10.888, Z = 2; beta = 106.95° V = 1,279.21 Den(Calc)= 2.86

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): 2.872(1), 11.51(1), 3.065(0.47),

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

Mellini M , Merlino S , Rossi G , American Mineralogist , 62 (1977) p.1114-1120, The crystal structure of tuscanite, Note Sample from the pumice deposit in Pitigliano, Tuscany, Italy

Physical Properties of Tuscanite

Cleavage:

[100] Distinct

Color:

Colorless.

Density:

2.83

Diaphaniety:

Transparent

Habit:

Platy - Sheet forms (e.g. micas).

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Tuscanite

Gladstone-Dale:

CI meas= -0.002 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2054,KPDmeas= 0.2075,KC= 0.2072

Optical Data:

Biaxial (-), a=1.581, b=1.59, g=1.591, bire=0.0100, 2V(Calc)=36, 2V(Meas)=40.

Calculated Properties of Tuscanite

Electron Density:

r_electron=2.82 gm/cc
note: r_Tuscanite=2.83 gm/cc.

Fermion Index

Fermion Index = 0.00869
Boson Index = 0.99131

Photoelectric:

PE_Tuscanite= 4.00 barns/electron
U=PE_Tuscanite x r_electron= 11.27 barns/cc.

Radioactivity:

GRapi = 45.95 (Gamma Ray American Petroleum Institute Units)

Estimated Radioactivity from Tuscanite - barely detectable

Tuscanite Classification

Dana Class:

73.1.2.2 (73)Phyllosilicate Condensed Tetrahedral Sheets

(73.1)with double layers

(73.1.2)Latiumite group

73.1.2.1 Latiumite (Ca,K)8(Al,Mg,Fe)(Si,Al)10O25(SO4) P 2₁ 2

73.1.2.2 Tuscanite K(Ca,Na)6(Si,Al)10O22(SO4,CO3,(OH)2)·(H2O) P 2₁/a 2/m

Strunz Class:

VIII/H.06-20 VIII - Silicates

VIII/H - Phyllosilicates (layered), Tetragonal or pseudotetragonal layered structures [Si4O10]4- and others

VIII/H.06 - Latiumite - Tuscanite series

VIII/H.06-10 Latiumite (Ca,K)8(Al,Mg,Fe)(Si,Al)10O25(SO4) P 2₁ 2

VIII/H.06-20 Tuscanite K(Ca,Na)6(Si,Al)10O22(SO4,CO3,(OH)2)·(H2O) P 2₁/a 2/m

Other Tuscanite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

Search for Tuscanite using:

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

Visit our Advertisers for Tuscanite :
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 Tuscanite Mineral Data :

Ask about Tuscanite 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 Tuscanite Specimen Label here :

Tuscanite

K(Ca,Na)6(Si,Al)10O22(SO4,CO3,(OH)2)·(H2O)
Dana No: 73.1.2.2 Strunz No: VIII/H.06-20
Locality:

Notes: