Yamhamelachite
The first approved Cr diphosphate mineral.
Other diphosphate minerals (also known from the type-locality area) include anastasenkoite, lisanite, nabateaite, and shasuite.
Also compare pyrocoproite, pyrophosphite, arnhemite, canaphite, and wooldridgeite.
Other Cr-bearing phosphate minerals are embreyite and vauquelinite, but these are chromate-phosphates.
In a few cases V is marginally more abundant than Cr, indicating the presence of a potentially new mineral with the formula KVP2O7 (Galuskin et al., 2025).
Unique Identifiers
IMA Classification of Yamhamelachite
Classification of Yamhamelachite
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
A : Polyphosphates, etc., without OH and H2O; dimers of corner-sharing RO4 tetrahedra.
Mineral Symbols
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ymm | 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 Yamhamelachite
Chemistry of Yamhamelachite
Crystallography of Yamhamelachite
β = 106.712(5)°
X-Ray Powder Diffraction
| d-spacing | Intensity |
|---|---|
| 5.747 Å | (96) |
| 5.255 Å | (23) |
| 3.905 Å | (82) |
| 3.380 Å | (33) |
| 2.997 Å | (68) |
| 2.956 Å | (28) |
| 2.929 Å | (100) |
| 2.926 Å | (61) |
Type Occurrence of Yamhamelachite
Other Language Names for Yamhamelachite
Related Minerals - Strunz-mindat Grouping
| 8.FA. | Phosphocyclite-(Fe) | Fe2+2(P4O12) |
| 8.FA. | Phosphocyclite-(Ni) | Ni2(P4O12) |
| 8.FA. | Grahampearsonite | Ca2P2O7 |
| 8.FA. | Bakakinite | Ca2V2O7 |
| 8.FA. | Lisanite | CaNiP2O7 |
| 8.FA. | Shasuite | CaNi3(P2O7)2 |
| 8.FA. | Nabateaite | Fe2P2O7 |
| 8.FA. | Samraite | Ni2P2O7 |
| 8.FA. | Anastasenkoite | CaFe2+(P2O7) |
| 8.FA.05 | Blossite | α-Cu2(V2O7) |
| 8.FA.10 | Ziesite | β-Cu2(V2O7) |
| 8.FA.15 | 'UM1999-17:O:PbV' | Pb4V2O9 or Pb4(VO4)2O |
| 8.FA.15 | Chervetite | Pb2(V2O7) |
| 8.FA.20 | 'Pyrocoproite' | (K,Na)2Mg(P2O7) |
| 8.FA.20 | 'Pyrophosphite' | K2Ca(P2O7) |
| 8.FA.25 | Petewilliamsite | (Ni,Co)30(As2O7)15 |
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) | 14.7520% | 4,573 | 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 Yamhamelachite
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References for Yamhamelachite
Localities for Yamhamelachite
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- 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.
Israel (TL) | |
| Galuskin +1 other reference |
Dead Sea