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Norsethite
A valid IMA mineral species
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About Norsethite
Formula:
BaMg(CO3)2
Colour:
Colorless, cloudy white
Lustre:
Sub-Vitreous, Resinous, Waxy, Pearly
Hardness:
3½
Specific Gravity:
3.84
Crystal System:
Trigonal
Member of:
Name:
Named in 1959 by Mary Emma Mrose, E. C. T. Chao, Joseph James Fahey, and Charles Milton in honor of Keith Norseth (1927–1991), geologist for the Westvaco Mine, west of Green River, Wyoming, USA.
Isostructural with:
Unique Identifiers
Mindat ID:
2934
Long-form identifier:
mindat:1:1:2934:2
IMA Classification of Norsethite
Approved
First published:
1961
Classification of Norsethite
5.AB.30
5 : CARBONATES (NITRATES)
A : Carbonates without additional anions, without H2O
B : Alkali-earth (and other M2+) carbonates
5 : CARBONATES (NITRATES)
A : Carbonates without additional anions, without H2O
B : Alkali-earth (and other M2+) carbonates
14.2.2.1
14 : ANHYDROUS NORMAL CARBONATES
2 : AB(XO3)2
14 : ANHYDROUS NORMAL CARBONATES
2 : AB(XO3)2
11.5.3
11 : Carbonates
5 : Carbonates of Sr and Ba
11 : Carbonates
5 : Carbonates of Sr and Ba
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Nst | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Nst | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Norsethite
Sub-Vitreous, Resinous, Waxy, Pearly
Transparency:
Transparent, Translucent
Colour:
Colorless, cloudy white
Streak:
White
Hardness:
3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Very Good
{1011}
{1011}
Fracture:
Hackly
Density:
3.84 g/cm3 (Measured) 3.84 g/cm3 (Calculated)
Optical Data of Norsethite
Type:
Uniaxial (-)
RI values:
nω = 1.694 nε = 1.519
Birefringence:
0.025
Max. Birefringence:
δ = 0.175
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Pleochroism:
Non-pleochroic
Chemistry of Norsethite
Mindat Formula:
BaMg(CO3)2
Element Weights:
Elements listed:
Chemical Analysis
Oxide wt%:
| 1 | |
|---|---|
| BaO | 53.11 % |
| MgO | 11.28 % |
| MnO | 4.68 % |
| Total: | 69.07 % |
Sample references:
Crystallography of Norsethite
Crystal System:
Trigonal
Class (H-M):
32 - Trapezohedral
Space Group:
R32
Cell Parameters:
a = 5.02 Å, c = 16.75 Å
Ratio:
a:c = 1 : 3.337
Unit Cell V:
365.56 ų (Calculated from Unit Cell)
Z:
3
Morphology:
Usually tabular plates with large (0001), rarely rhombohedral with (0001), {1011}, {1010}, and {1120}.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0010926 | Norsethite | Effenberger H, Zemann J (1985) Single crystal X-Ray investigation of norsethite, BaMg(CO3)2: one more mineral with an aplanar carbonate group Zeitschrift fur Kristallographie 171 275-280 |  | 1985 | synthetic | 0 | 293 |
| 0010925 | Norsethite | Effenberger H, Zemann J (1985) Single crystal X-Ray investigation of norsethite, BaMg(CO3)2: one more mineral with an aplanar carbonate group Zeitschrift fur Kristallographie 171 275-280 | | 1985 | synthetic | 0 | 293 |
| 0010924 | Norsethite | Effenberger H, Zemann J (1985) Single crystal X-Ray investigation of norsethite, BaMg(CO3)2: one more mineral with an aplanar carbonate group Zeitschrift fur Kristallographie 171 275-280 | | 1985 | synthetic | 0 | 293 |
| 0014695 | Norsethite | Lippmann F (1967) Die kristallstruktur des norsethit, BaMg(CO3)2, im vergleich zum dolomit, CaMg(CO3)2 Naturwissenschaften 54 514-514 | 1967 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.584 Å | (25) |
| 4.21 Å | (30) |
| 3.86 Å | (35) |
| 3.02 Å | (100) |
| 2.66 Å | (35) |
| 2.51 Å | (35) |
| 2.10 Å | (35) |
| 1.931 Å | (35) |
| 1.864 Å | (35) |
Comments:
ICDD 12-530
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 21 : Chemically precipitated carbonate, phosphate, iron formations | |
| 24 : Authigenic minerals in terrestrial sediments (see also #17) | |
| High-? alteration and/or metamorphism | |
| 32 : Ba/Mn/Pb/Zn deposits, including metamorphic deposits | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 36 : Carbonatites, kimberlites, and related igneous rocks | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
Kremikovtsi mine, Kremikovtsi, Stolichna Municipality, Sofia City Province, Bulgaria