Middendorfite
About Middendorfite
Unique Identifiers
IMA Classification of Middendorfite
Classification of Middendorfite
9 : SILICATES (Germanates)
E : Phyllosilicates
J : Unclassified phyllosilicates
Mineral Symbols
| Symbol | Source | Reference for Standard |
|---|---|---|
| Mdd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Middendorfite
on (001)
Optical Data of Middendorfite
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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Z = deep brown
Chemistry of Middendorfite
Crystallography of Middendorfite
β = 114.04(7)°
X-Ray Powder Diffraction
| d-spacing | Intensity |
|---|---|
| 12.28 Å | (100) |
| 2.840 Å | (90) |
| 2.634 Å | (88) |
| 4.31 Å | (81) |
| 2.366 Å | (76) |
| 1.669 Å | (64) |
| 3.555 Å | (62) |
Geological Environment
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Middendorfite
Synonyms of Middendorfite
Other Language Names for Middendorfite
Related Minerals - Strunz-mindat Grouping
| 9.EJ.05 | Lourenswalsite | (K,Ba)2(Ti,Mg,Ca,Fe)4(Si,Al,Fe)6O14(OH)12 |
| 9.EJ.15 | Lipuite | KNa8Mn3+5 Mg0.5[Si12O30(OH)4](PO4)O2(OH)2 · 4H2O |
| 9.EJ.20 | Odigitriaite | CsNa5Ca5[Si14B2O38]F2 |
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) | 8.4567% | 2,622 | 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 Middendorfite
Please feel free to link to this page.
References for Middendorfite
Localities for Middendorfite
Showing 1 localities.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Russia (TL) | |
| Pekov et al. (2006) |
Hilairitovoye pegmatite, 252 m level, Kirovskii apatite mine, Kukisvumchorr Mt, Murmansk Oblast, Russia