UM1992-36-SiO:FeHKMgMnNa
Excess alkalis and silica suggest the compound to be, possibly, a poorly-crystalline modulated phase. Somewhat siilar to 'sturtite' and stilpnomelane.
As particles 0.1-0.5 or 1-3 microns in diameter; the first group has (semi)hexagonal outlines. Found in 3 samples of charoitite, with charoite, K feldspar, aegirine, and tinaksite.
Rather not identical to neotocite.
Unique Identifiers
Similar Names
| UM1989-34-SiO:FeKMgMnNa | (K,Na,Sr)(Na,Ca)1.3(Mg,Na,Mn)2(Mg,Fe,Al)3(Si,Al)12O30 |
IMA Classification of UM1992-36-SiO:FeHKMgMnNa
Physical Properties of UM1992-36-SiO:FeHKMgMnNa
Optical Data of UM1992-36-SiO:FeHKMgMnNa
Based on recorded range of RI values above.
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.
Chemistry of UM1992-36-SiO:FeHKMgMnNa
water content likely variable
X-Ray Powder Diffraction
| d-spacing | Intensity |
|---|
Radioactivity
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 7.6758% | 2,379 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Other Information
Internet Links for UM1992-36-SiO:FeHKMgMnNa
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References for UM1992-36-SiO:FeHKMgMnNa
Localities for UM1992-36-SiO:FeHKMgMnNa
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The Locality List
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? - Indicates mineral may be doubtful at this locality.
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- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
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All localities listed without proper references should be considered as questionable.
Russia | |
| Lazebnik et al. (1992) +1 other reference |
