General Pumpellyite-(Mg) Information Chemical Formula: |
Ca2MgAl2(SiO4)(Si2O7)(OH)2•(H2O) |
Composition: |
Molecular Weight = 470.70 gm |
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Calcium 17.03 % Ca 23.83 % CaO |
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Magnesium 5.16 % Mg 8.56 % MgO |
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Aluminum 11.46 % Al 21.66 % Al2O3 |
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Silicon 17.90 % Si 38.29 % SiO2 |
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Hydrogen 0.86 % H 7.65 % H2O |
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Oxygen 47.59 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
Empirical Formula: |
Ca2MgAl2(SiO4)(Si2O7)(OH)2•(H2O) |
Environment: |
Meta-basalt or gabbroic rocks. |
IMA Status: |
Valid Species (Pre-IMA) 1925 |
Locality: |
Calumet mine, Houghton County, Keweenaw Peninisula, Michigan, USA. Link to MinDat.org Location Data. |
Name Origin: |
Named after the American geologist, R. Pumpelly (1837-1923). |
Name Pronunciation: |
Pumpellyite-(Mg) + Pronunciation |
Synonym: |
Pumpellyite |
| | Pumpellyite-(Mg) Image
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Pumpellyite-(Mg) Crystallography Axial Ratios: |
a:b:c =1.4939:1:3.2384 |
Cell Dimensions: |
a = 8.82, b = 5.904, c = 19.12, Z = 4; beta = 97.4° V = 987.35 Den(Calc)= 3.17 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: A2/m |
X Ray Diffraction: |
By Intensity(I/Io): 2.9(1), 2.74(0.5), 3.79(0.5), |
Crystal Structure:
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Mouse
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| Physical Properties of Pumpellyite-(Mg) Cleavage: |
{001} Good, {100} Good |
Color: |
Blue green, Olive green, Brown. |
Density: |
3.2 |
Diaphaneity: |
Translucent |
Fracture: |
Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces. |
Habit: |
Fibrous - Crystals made up of fibers. |
Habit: |
Massive - Lamellar - Distinctly foliated fine-grained forms. |
Habit: |
Spherical - Spherical, rounded aggregates. |
Hardness: |
5.5 - Knife Blade |
Luminescence: |
Non-fluorescent. |
Luster: |
Vitreous (Glassy) |
Streak: |
white |
| Optical Properties of Pumpellyite-(Mg) Gladstone-Dale: |
CI meas= 0.007 (Superior) - where the CI = (1-KPDmeas/KC) |
CI calc= -0.002 (Superior) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2182,KPDmeas= 0.2161,KC= 0.2177 Ncalc = 1.69 - 1.7 Optical Data: |
Biaxial (+), a=1.67-1.698, b=1.672-1.706, g=1.684-1.72, bire=0.0140-0.0220, 2V(Calc)=46-76, 2V(Meas)=10-50. Dispersion relatively strong. |
| Calculated Properties of Pumpellyite-(Mg) Electron Density: |
Bulk Density (Electron Density)=3.18 gm/cc |
note: Specific Gravity of Pumpellyite-(Mg) =3.17 gm/cc. Fermion Index: |
Fermion Index = 0.01 |
Boson Index = 0.99 Photoelectric: |
PEPumpellyite-(Mg) = 3.23 barns/electron |
U=PEPumpellyite-(Mg) x rElectron Density= 10.27 barns/cc. Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) |
Pumpellyite-(Mg) is Not Radioactive | Pumpellyite-(Mg) Classification Dana Class: |
58.02.02.07 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups |
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(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2) |
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(58.02.02)Pumpellyite group |
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Strunz Class: |
09.BG.20 09 - SILICATES (Germanates) |
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09.B - Sorosilicates |
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09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups; |
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| Other Pumpellyite-(Mg) Information References: |
NAME( Duda&Rejl90) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8) |
See Also: |
Links to other databases for Pumpellyite-(Mg) : |
1 - Am. Min. Crystal Structure Database 2 - Athena 3 - Franklin Minerals(Dunn) 4 - GeoScienceWorld 5 - Google Images 6 - Google Scholar 7 - MinDAT 8 - Mineralienatlas (Deutsch) 9 - Online Mineral Museum 10 - QUT Mineral Atlas 11 - Ruff.Info Search for Pumpellyite-(Mg) using: Visit our Advertisers for Pumpellyite-(Mg) : A Bijoux Google Search for Pumpellyite-(Mg)Adam's Minerals Google Search for Pumpellyite-(Mg) Cape Minerals Google Search for Pumpellyite-(Mg) Dakota Matrix Minerals Google Search for Pumpellyite-(Mg) Excalibur Mineral Corp. Google Search for Pumpellyite-(Mg) Exceptional Minerals Google Search for Pumpellyite-(Mg) John Betts Fine Minerals Search for Pumpellyite-(Mg) McDougall Minerals Google Search for Pumpellyite-(Mg) Mineral News Website Link Rock and Mineral Shows Google Search for Pumpellyite-(Mg) Weinrich Minerals, Inc. Google Search for Pumpellyite-(Mg) Ask about Pumpellyite-(Mg) here : Print or Cut-and-Paste your Pumpellyite-(Mg) Specimen Label here :
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