|
| Home | Crystal | jmol | jPOWD | Chem | X Ray | Dana | Strunz | Properties | A to Z | Images | Share | News | Help | About |
General Coombsite Information |
|||
 Chemical Formula: |
K(Mn++,Fe++,Mg)13(Si,Al)18O42(OH)14 | ||
| Composition: |
Molecular Weight = 2,127.66 gm | ||
| Potassium 1.84 % K 2.21 % K2O | |||
| Magnesium 1.49 % Mg 2.46 % MgO | |||
| Manganese 20.14 % Mn 26.01 % MnO | |||
| Aluminum 5.71 % Al 10.78 % Al2O3 | |||
| Iron 10.24 % Fe 13.17 % FeO | |||
| Silicon 17.82 % Si 38.12 % SiO2 | |||
| Hydrogen 0.66 % H 5.93 % H2O | |||
| Oxygen 42.11 % O | |||
| ______ ______ | |||
| 100.00 % 98.68 % = TOTAL OXIDE | |||
| Empirical Formula: |
KMn2+7.8Fe2+3.9Mg1.3Si13.5Al4.5O42(OH)14 | ||
| IMA Status: |
Approved IMA 1996 (Dana # Added) | ||
| Locality: |
Watson's Beach, Otago, South Island, New Zealand Link to MinDat.org Location Data. | ||
| Name Origin: |
Named for D.S Coombs of the University of Otago, New Zealand. | ||
| Synonym: |
IMA1989-058 | ||
Coombsite Image | |||
|
Images:
|
|
||
Coombsite Crystallography |
|||
| Axial Ratios: |
a:c = 1:2.46415 | ||
| Cell Dimensions: |
a = 11.828, c = 29.146, Z = 3; V = 3,531.28 Den(Calc)= 3.00 | ||
| Crystal System: |
TrigonalSpace Group: R 3 or R 3 | ||
| X Ray Diffraction: |
By Intensity(I/Io): 9.68(1), 2.556(0.9), 2.793(0.7), | ||
Physical Properties of Coombsite |
|||
| Cleavage: |
{???} Good | ||
| Color: |
Brown. | ||
| Density: |
3 | ||
| Diaphaneity: |
Translucent | ||
| Luster: |
Vitreous (Glassy) | ||
| Streak: |
brownish yellow | ||
Optical Properties of Coombsite |
|||
| Gladstone-Dale: |
CI meas= 0.019 (Superior) - where the CI = (1-KPDmeas/KC) CI calc= 0.019 (Superior) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.2032,KPDmeas= 0.2032,KC= 0.207 Ncalc = 1.62 |
||
| Optical Data: |
Uniaxial (-), e=1.6, w=1.619, bire=0.0190. | ||
Calculated Properties of Coombsite |
|||
| Electron Density: |
Bulk Density (Electron Density)=2.93 gm/cc note: Specific Gravity of Coombsite =3.00 gm/cc. |
||
| Fermion Index: |
Fermion Index = 0.01 Boson Index = 0.99 |
||
| Photoelectric: |
PECoombsite = 9.23 barns/electron U=PECoombsite x relectron= 27.08 barns/cc. |
||
| Radioactivity: |
GRapi = 25.94 (Gamma Ray American Petroleum Institute Units)
Estimated Radioactivity from Coombsite |
||
Coombsite Classification |
|||
| Dana Class: |
74.01.04.02 (74)Phyllosilicate Modulated Layers | ||
| (74.01)with joined islands | |||
| (74.01.04)Dana Group | |||
| Strunz Class: |
09.EG.35 09 - SILICATES (Germanates) | ||
| 09.E - Phyllosilicates | |||
| 09.EG -Double nets with 6-membered and larger rings | |||
Other Coombsite Information |
|||
| References: |
PHYS. PROP.(37th List of New Min.,Min. Mag.,1996) OPTIC PROP.(37th List of New Min.,Min. Mag.,19) | ||
| See Also: |
Links to other databases for Coombsite : 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 Search for Coombsite using: Visit our Advertisers for Coombsite : A Bijoux Google Search for CoombsiteAdam's Minerals Google Search for Coombsite Cape Minerals Google Search for Coombsite Dakota Matrix Minerals Google Search for Coombsite Excalibur Mineral Corp. Google Search for Coombsite Exceptional Minerals Google Search for Coombsite John Betts Fine Minerals Search for Coombsite McDougall Minerals Google Search for Coombsite Mineral News Website Link Rock and Mineral Shows Google Search for Coombsite Weinrich Minerals, Inc. Google Search for Coombsite Ask about Coombsite here : Print or Cut-and-Paste your Coombsite Specimen Label here :
|
||
- barely detectable