Rankinite Mineral Data

General Rankinite Information

Chemical Formula:

Ca3Si2O7

Composition:

Molecular Weight = 288.40 gm

Calcium 41.69 % Ca 58.33 % CaO

Silicon 19.48 % Si 41.67 % SiO₂

Oxygen 38.83 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₃Si₂O₇

Environment:

In high-temperature calc-silicate skarns.

IMA Status:

Valid Species (Pre-IMA) 1942

Locality:

From Scawt Hill, near Larne, Co. Antrim, Ireland. Link to MinDat.org Location Data.

Name Origin:

Named for George Atwater Rankin (1884-?), physical chemist of the Geophysical Laboratory, Washington, D.C., USA,

Name Pronunciation:

Rankinite + Pronunciation

Synonym:

ICSD 2282

PDF 22-539

Rankinite Crystallography

Axial Ratios:

a:b:c =1.188:1:0.884

Cell Dimensions:

a = 10.55, b = 8.88, c = 7.85, Z = 4; beta = 120.1° V = 636.25 Den(Calc)= 3.01

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/a

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

By Intensity(I/I_o): 2.72(1), 3.18(0.8), 4.48(0.7),

Physical Properties of Rankinite

Cleavage:

None

Color:

Colorless, White.

Density:

2.96 - 3, Average = 2.98

Diaphaneity:

Transparent

Hardness:

5.5 - Knife Blade

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Rankinite

Gladstone-Dale:

CI meas= -0.035 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2142,KPDmeas= 0.2164,KC= 0.2092
Ncalc = 1.62 - 1.63

Optical Data:

Biaxial (+), a=1.64-1.641, b=1.644, g=1.65, bire=0.0090-0.0100, 2V(Calc)=72-80, 2V(Meas)=64.

Calculated Properties of Rankinite

Electron Density:

Bulk Density (Electron Density)=3.01 gm/cc
note: Specific Gravity of Rankinite =3.01 gm/cc.

Fermion Index:

Fermion Index = 0.0098448395
Boson Index = 0.9901551605

Photoelectric:

PE_Rankinite= 5.85 barns/electron
U=PE_Rankinite x rElectron Density= 17.59 barns/cc.

Radioactivity:

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

Rankinite Classification

Dana Class:

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

(55.03)with cations in [7] coordination

(55.03.01)Dana Group

55.03.01.01 Rankinite Ca3Si2O7 P 2₁/a 2/m

Strunz Class:

09.BC.15 09 - SILICATES (Germanates)

09.B - Sorosilicates

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

09.BC.15 Rankinite Ca3Si2O7 P 2₁/a 2/m

Other Rankinite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

See Also:

Links to other databases for Rankinite :
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 Rankinite Specimen Label here :

Rankinite

Ca3Si2O7
Dana No: 55.03.01.01 Strunz No: 09.BC.15
Locality:

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