Gugiaite Mineral Data

General Gugiaite Information

Chemical Formula:

Ca2BeSi2O7

Composition:

Molecular Weight = 257.33 gm

Calcium 31.15 % Ca 43.58 % CaO

Beryllium 3.50 % Be 9.72 % BeO

Silicon 21.83 % Si 46.70 % SiO₂

Oxygen 43.52 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂Be(Si₂O₇)

Environment:

In cavities in skarns and melanite adjacent to an alkalic syenite.

IMA Status:

Approved IMA 1962

Locality:

Near the village of Gugia, otherwise unlocated in China. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Gugiaite

Synonym:

ICSD 31234

PDF 15-199

Gugiaite Crystallography

Axial Ratios:

a:c = 1:0.67617

Cell Dimensions:

a = 7.43, c = 5.024, Z = 2; V = 277.35 Den(Calc)= 3.08

Crystal System:

Tetragonal - Scalenohedral H-M Symbol (4 2m) Space Group: P 42₁m

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

By Intensity(I/I_o): 2.765(1), 1.485(0.7), 1.709(0.7),

Physical Properties of Gugiaite

Cleavage:

{010} Perfect, {001} Distinct, {110} Indistinct

Color:

Colorless.

Density:

3.03

Diaphaneity:

Transparent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Hardness:

3-4 - Calcite-Fluorite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Gugiaite

Gladstone-Dale:

CI meas= -0.04 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.023 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2169,KPDmeas= 0.2205,KC= 0.212
Ncalc = 1.64 - 1.65

Optical Data:

Uniaxial (+), w=1.664, e=1.672, bire=0.0080.

Calculated Properties of Gugiaite

Electron Density:

Bulk Density (Electron Density)=3.06 gm/cc
note: Specific Gravity of Gugiaite =3.08 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_Gugiaite= 4.70 barns/electron
U=PE_Gugiaite x rElectron Density= 14.40 barns/cc.

Radioactivity:

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

Gugiaite Classification

Dana Class:

55.04.02.06 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.04)with cations in [8] and lower coordination

(55.04.02)Fresnoite group

55.04.02.01 Fresnoite Ba2TiSi2O8 P 4bm 4mm

55.04.02.02 Hardystonite Ca2ZnSi2O7 P 42₁m 4 2m

55.04.02.03 Jeffreyite (Ca,Na)2(Be,Al)Si2(O,OH)7 C 222₁ 2 2 2

55.04.02.04 Leucophanite (Na,Ca)2BeSi2(O,OH,F)7 P1 1

55.04.02.05 Meliphanite (Ca,Na)2Be[(Si,Al)2O6(F,OH)] I 4 4

55.04.02.06 Gugiaite Ca2BeSi2O7 P 42₁m 4 2m

Strunz Class:

09.BB.10 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BB -Si2O7 groups, without non-tetrahedral anions;

09.BB.10 Akermanite Ca2MgSi2O7 P 42₁m 4 2m

09.BB.10 Cebollite Ca5Al2(SiO4)3(OH)4 Unk Ortho

09.BB.10 Gugiaite Ca2BeSi2O7 P 42₁m 4 2m

09.BB.10 Gehlenite Ca2Al(AlSi)O7 P 42₁m 4 2m

09.BB.10 Jeffreyite (Ca,Na)2(Be,Al)Si2(O,OH)7 C 222₁ 2 2 2

09.BB.10 Hardystonite Ca2ZnSi2O7 P 42₁m 4 2m

09.BB.10 Melilite (Ca,Na)2(Al,Mg,Fe)(Si,Al)2O7 P 42₁m 4 2m

09.BB.10 Okayamalite! Ca2B2SiO7 P 42₁m 4 2m

Other Gugiaite Information

References:

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

See Also:

Links to other databases for Gugiaite :
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

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

Gugiaite

Ca2BeSi2O7
Dana No: 55.04.02.06 Strunz No: 09.BB.10
Locality:

Notes:

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