Description
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AMIS0104 Manganese ore, 35.31%, Namibia
Origin of material: Otjosondu manganese field is situated just north of the Okahandja Lineament some 150km north east of Windhoek. The Otjosondu manganese ore is associated with banded iron formation consisting of hematite-quartzite and iron-rich gneisses. The entire Otjosondu area has undergone Damaran metamorphism of at least upper amphibolite grade. The original paragenesis has been altered to a silica-rich metamorphic manganese mineral assemblage. This ore was supplied by Otjozondu Mining.
Mineral and chemical composition: In pure manganese ores the critical assemblage braunite + haematite + jacobsite + rhodonite is frequently developed, whereas interlayered impure silicate ores bear various proportions of spessartine, Mn3+-bearing andradite–calderite and andradite garnets, rhodonite, manganoan aegirine–augite, aegirine, Ba–K–Na-feldspars, barite and rare kinoshitalite. Petrological constraints derived from country rock lithologies indicate peak metamorphic conditions of 660–700°C at estimated pressures of 3.5–4.5 kbar. Numerous Ba-rich pegmatitic veins restricted to the ore horizons testify to the production of partial melts from siliciclastic strata within the manganese formations.
Recommended Concentration and two “Between Laboratory” Standard Deviations
Certified Concentrations
|
Mn XRF |
35.31 |
± |
1.06 |
% |
|
Mn M/ICP |
35.49 |
± |
2.08 |
% |
|
Zn M/ICP |
142 |
± |
16 |
ppm |
|
Ba M/ICP |
2.86 |
± |
0.23 |
% |
|
Co M/ICP |
240 |
± |
21 |
ppm |
|
SG |
4.32 |
± |
0.24 |
|
Provisional Concentrations
|
As M/ICP |
116 |
± |
14 |
ppm |
|
Cu M/ICP |
192 |
± |
26 |
ppm |
|
P M/ICP |
192 |
± |
46 |
ppm |
|
Sr M/ICP |
309 |
± |
38 |
ppm |
|
V M/ICP |
108 |
|
ppm |
|
Major Element Certified Concentrations
|
Al2O3 |
2.20 |
± |
0.06 |
% |
|
CaO |
1.34 |
± |
0.06 |
% |
|
Fe2O3 |
20.78 |
± |
0.38 |
% |
|
K2O |
0.26 |
± |
0.02 |
% |
|
SiO2 |
18.30 |
± |
0.30 |
% |
|
TiO2 |
0.27 |
± |
0.02 |
% |
Major Element Provisional Concentrations
|
MgO |
0.35 |
± |
0.06 |
% |
|
LOI |
3.28 |
± |
0.70 |
% |
Major Element Informational Values
|
Cr2O3 |
0.03 |
% |
|
|
|
Na2O |
0.10 |
% |
|
|
|
S ICP |
0.32 |
% |
|
|
Please download the certificate for more information
