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Ramsdellite Mineral Data
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General Ramsdellite Information
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 Chemical Formula: |
MnO2 |
| Composition: |
Molecular Weight = 86.94 gm |
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Manganese 63.19 % Mn 100.00 % MnO2 |
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Oxygen 36.81 % O |
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______ ______ |
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100.00 % 100.00 % = TOTAL OXIDE |
| Empirical Formula: |
Mn4+O2 |
| Environment: |
Manganese deposits with pyrolusite. |
| IMA Status: |
Valid Species (Pre-IMA) 1943 |
| Locality: |
Lake Valley, Sierra County, New Mexico. Link to MinDat.org Location Data. |
| Name Origin: |
Named after the American mineralogist, Lewis S. Ramsdell (1895-1975), of the University of Michigan, who first described the mineral. |
| Name Pronunciation: |
Ramsdellite + Pronunciation  |
| Synonym: |
Groutellite - pseudomorph of ramsdellite after groutite |
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ICSD 78331 |
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PDF 44-142 |
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Ramsdellite Image |
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Images:
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Ramsdellite
Comments: Large mass of radiating ramsdellite crystals with terminated crystals.
Location: Lake Valley District, Sierra Co., New Mexico, USA.
Scale: 11x10x8 cm.
© John Betts - Fine Minerals |
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Ramsdellite Crystallography
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| Axial Ratios: |
a:b:c =0.4889:1:0.3091 |
| Cell Dimensions: |
a = 4.533, b = 9.27, c = 2.866, Z = 4; V = 120.43 Den(Calc)= 4.79 |
| Crystal System: |
Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbnm |
| X Ray Diffraction: |
By Intensity(I/Io): 4.06(1), 2.32(0.65), 2.55(0.6), |
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Physical Properties of Ramsdellite
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| Cleavage: |
{???} Good |
| Color: |
Iron black, Black, Steel gray. |
| Density: |
4.37 |
| Diaphaneity: |
Opaque |
| Fracture: |
Brittle - Generally displayed by glasses and most non-metallic minerals. |
| Habit: |
Granular - Generally occurs as anhedral to subhedral crystals in matrix. |
| Habit: |
Massive - Fibrous - Distinctly fibrous fine-grained forms. |
| Habit: |
Platy - Sheet forms (e.g. micas). |
| Hardness: |
3 - Calcite |
| Luster: |
Metallic |
| Streak: |
brownish black |
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Optical Properties of Ramsdellite
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| Optical Data: |
NCalc= 2.89 - from Gladstone-Dale relationship (KC = 0.394) where Ncalc=Dcalc*KC+1
NCalc= 2.72 - from Gladstone-Dale relationship (KC = 0.394) where Ncalc=Dmeas*KC+1 |
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Calculated Properties of Ramsdellite
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| Electron Density: |
Bulk Density (Electron Density)=4.52 gm/cc
note: Specific Gravity of Ramsdellite =4.79 gm/cc.
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| Fermion Index: |
Fermion Index = 0.0001766733
Boson Index = 0.9998233267 |
| Photoelectric: |
PERamsdellite = 16.61 barns/electron
U=PERamsdellite x rElectron Density= 75.02 barns/cc.
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| Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Ramsdellite is Not Radioactive |
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Ramsdellite Classification
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| Dana Class: |
04.04.07.01 (04)Simple Oxides |
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(04.04)with a cation charge of 4+ (A++++ O2) |
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(04.04.07)Dana Group |
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04.04.07.01 Ramsdellite MnO2 Pbnm 2/m 2/m 2/m |
| Strunz Class: |
04.DB.15a 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate |
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04.D - Metal:Oxygen = 1:2 and similar |
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04.DB -With medium-sized cations; chains of edge-sharing octahedra |
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04.DB.15a Paramontroseite VO2 Pbnm 2/m 2/m 2/m |
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04.DB.15a Ramsdellite MnO2 Pbnm 2/m 2/m 2/m |
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Other Ramsdellite Information
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| References: |
NAME( MinRec) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) |
| See Also: |
Links to other databases for Ramsdellite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Glendale Community College
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - HyperPhysics
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - WWW-MINCRYST
19 - YupRocks
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Print or Cut-and-Paste your Ramsdellite Specimen Label here :
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Ramsdellite
MnO2
Dana No: 04.04.07.01 Strunz No: 04.DB.15a
Locality:
Notes:
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