General Tilleyite Information Chemical Formula: |
Ca5Si2O7(CO3)2 |
Composition: |
Molecular Weight = 488.58 gm |
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Calcium 41.02 % Ca 57.39 % CaO |
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Silicon 11.50 % Si 24.60 % SiO2 |
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Carbon 4.92 % C 18.02 % CO2 |
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Oxygen 42.57 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
Ca5Si2O7(CO3)2 |
Environment: |
In the contact metamorphic zone between igneous rocks and limestones, formed at low pressure and high temperature. |
IMA Status: |
Valid Species (Pre-IMA) 1933 |
Locality: |
Crestmore quarry, 5 miles NW of Riverside, Riverside County, California. Link to MinDat.org Location Data. |
Name Origin: |
Named for Cecil Edgar Tilley (1894-1973), British petrologist, Cambridge University, Cambridge, England. |
Name Pronunciation: |
Tilleyite + Pronunciation |
Synonym: |
ICSD 14256 |
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PDF 24-184 |
| | Tilleyite Image
Images:
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Tilleyite Crystallography Axial Ratios: |
a:b:c =1.4631:1:0.7428 |
Cell Dimensions: |
a = 15.025, b = 10.269, c = 7.628, Z = 4; beta = 105.833° V = 1,132.29 Den(Calc)= 2.87 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 21/a |
X Ray Diffraction: |
By Intensity(I/Io): 3.005(1), 3.095(0.85), 2.895(0.65), |
Crystal Structure:
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Mouse
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| Physical Properties of Tilleyite Cleavage: |
{100} Perfect, {101} Good |
Color: |
Colorless, White. |
Density: |
2.84 |
Diaphaneity: |
Transparent to Translucent |
Streak: |
white |
| Optical Properties of Tilleyite Gladstone-Dale: |
CI meas= -0.064 (Fair) - where the CI = (1-KPDmeas/KC) |
CI calc= -0.053 (Good) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2208,KPDmeas= 0.2231,KC= 0.2097 Ncalc = 1.6 Optical Data: |
Biaxial (+), a=1.612-1.617, b=1.632-1.635, g=1.652-1.654, bire=0.0370-0.0400, 2V(Calc)=88-90, 2V(Meas)=85-90. Dispersion r < v. |
| Calculated Properties of Tilleyite Electron Density: |
Bulk Density (Electron Density)=2.87 gm/cc |
note: Specific Gravity of Tilleyite =2.87 gm/cc. Fermion Index: |
Fermion Index = 0.0066679407 |
Boson Index = 0.9933320593 Photoelectric: |
PETilleyite = 5.53 barns/electron |
U=PETilleyite x rElectron Density= 15.84 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Tilleyite is Not Radioactive | Tilleyite Classification Dana Class: |
56.02.09.01 (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O |
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(56.02)with cations in [4] and/or >[4] coordination |
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(56.02.09)Tilleyite - Killalaite group |
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Strunz Class: |
09.BE.08.2 09 - SILICATES (Germanates) |
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09.B - Sorosilicates |
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09.BE -Si2O7 groups with additional anions; |
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| Other Tilleyite Information References: |
NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65) |
See Also: |
Links to other databases for Tilleyite : |
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 Search for Tilleyite using: Visit our Advertisers for Tilleyite : A Bijoux Google Search for TilleyiteAdam's Minerals Google Search for Tilleyite Cape Minerals Google Search for Tilleyite Dakota Matrix Minerals Google Search for Tilleyite Excalibur Mineral Corp. Google Search for Tilleyite Exceptional Minerals Google Search for Tilleyite John Betts Fine Minerals Search for Tilleyite McDougall Minerals Google Search for Tilleyite Mineral News Website Link Rock and Mineral Shows Google Search for Tilleyite Weinrich Minerals, Inc. Google Search for Tilleyite Ask about Tilleyite here : Print or Cut-and-Paste your Tilleyite Specimen Label here :
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