Bertossaite Mineral Data

General Bertossaite Information

Chemical Formula:

Li2CaAl4(PO4)4(OH)4

Composition:

Molecular Weight = 609.80 gm

Lithium 2.28 % Li 4.90 % Li₂O

Calcium 6.57 % Ca 9.20 % CaO

Aluminum 17.70 % Al 33.44 % Al₂O₃

Phosphorus 20.32 % P 46.55 % P₂O₅

Hydrogen 0.66 % H 5.91 % H₂O

Oxygen 52.47 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Li₂CaAl₄(PO₄)₄(OH)₄

Environment:

Ca analog of palermoite.

IMA Status:

Approved IMA 1966

Locality:

Buranga lithium pegmatite, Gatumba, Rwanda. Link to MinDat.org Location Data.

Name Origin:

Named for Antonio Bertossa, director of the Geological Survey of Rwanda.

Name Pronunciation:

Bertossaite + Pronunciation

Bertossaite Image

Images:

Bertossaite

Comments: Pale pinkish crystalline bertossaite with yellowish apatite and blue lazulite.
Location: Buranga Pegmatite, near Gatumba, Gisenyi, Rwanda. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bertossaite Crystallography

Axial Ratios:

a:b:c =0.7298:1:0.4596

Cell Dimensions:

a = 11.48, b = 15.73, c = 7.23, Z = 4; V = 1,305.60 Den(Calc)= 3.10

Crystal System:

Orthorhombic Space Group: Imaa,Iaa2

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

By Intensity(I/I_o): 3.056(1), 3.104(0.7), 3.286(0.7),

Physical Properties of Bertossaite

Cleavage:

{100} Good

Color:

Light pink.

Density:

3.1

Fracture:

Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.

Hardness:

6 - Orthoclase

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Bertossaite

Gladstone-Dale:

CI meas= 0.021 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2045,KPDmeas= 0.2045,KC= 0.2089
Ncalc = 1.65

Optical Data:

Biaxial (-), a=1.624, b=1.636, g=1.642, bire=0.0180

Calculated Properties of Bertossaite

Electron Density:

Bulk Density (Electron Density)=3.07 gm/cc
note: Specific Gravity of Bertossaite =3.10 gm/cc.

Fermion Index:

Fermion Index = 0.0020489543
Boson Index = 0.9979510457

Photoelectric:

PE_Bertossaite= 2.33 barns/electron
U=PE_Bertossaite x rElectron Density= 7.15 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Bertossaite is Not Radioactive

Bertossaite Classification

Dana Class:

41.07.01.02 (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen

(41.07)where (A B)m (XO4)4 Zq

(41.07.01)Palermoite Group

41.07.01.01 Palermoite (Sr,Ca)(Li,Na)2Al4(PO4)4(OH)4 I mmm 2/m 2/m 2/m

41.07.01.02 Bertossaite Li2CaAl4(PO4)4(OH)4 Imaa,Iaa2 Ortho

Strunz Class:

08.BH.25 08 - PHOSPHATES, ARSENATES, VANADATES

08.B - Phosphates, etc. with Additional Anions, without H2O

08.BH -With medium-sized and large cations, (OH,etc.):RO4 = 1:1

08.BH.25 Bertossaite Li2CaAl4(PO4)4(OH)4 Imaa,Iaa2 Ortho

08.BH.25 Palermoite (Sr,Ca)(Li,Na)2Al4(PO4)4(OH)4 I mmm 2/m 2/m 2/m

Other Bertossaite 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 Bertossaite :
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

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

Bertossaite

Li2CaAl4(PO4)4(OH)4
Dana No: 41.07.01.02 Strunz No: 08.BH.25
Locality:

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